Single crystals of the high-temperature modification of iron(II) sulfate, β-FeSO₄, were grown using chemical transport reactions with HCl as transport agent. The title compound crystallizes in the CuSO₄ structure (space group Pnma) and is isotypic with other divalent metal sulfates M^IISO₄ adopting this structure type (M = Mg, Co, Zn). The coordination polyhedron of the Fe²⁺ cation is a distorted octahedron ( symmetry) with a [2+2+2] distribution of bond lengths. By edge-sharing of the [FeO₆] octahedra, [FeO_4/2O_2/1]_∞ chains are established parallel to [010]; these are linked into a framework by corner-sharing with slightly distorted SO₄ tetrahedra (m symmetry).

Single crystals of lutetium oxide iodide, LuOI, were obtained as a by-product of the reaction of lutetium metal, rhenium powder and lutetium triiodide, LuI₃, in a sealed tantalum container. LuOI crystallizes in the tetragonal PbFCl-type of structure (matlockite), where Lu, O and I are situated on positions with 4mm, m2 and 4mm symmetry, respectively.

The single-crystal structure of the title compound {systematic name: poly[tetraaquatri-μ₂-sulfato-diholmium(III)]}, [Ho₂(SO₄)₃(H₂O)₄]_n, features two-dimensional holmium(III) sulfate layers constructed by eight-coordinate holmium and sulfate groups. The coordination about Ho includes four O atoms from bridging sulfate ions. One S atom makes three S—O—Ho linkages through bridging O atoms, while a second S atom lies on a twofold axis and makes two S—O—Ho linkages. The coordination of each Ho atom is completed by four water molecules, which act as terminal ligands of Ho³⁺.

The crystal structure of YMgGa, yttrium magnesium gallide, is isotypic with LaMgGa and crystallizes in the hexagonal ZrNiAl type structure. It consists of a three-dimensional network of Mg and Ga atoms, in which Y atoms fill channels. There are two crystallographically independent Ga sites. One Ga atom (Ga1) has three Mg atoms as near neighbours and six Y atoms at a slightly longer distance, giving rise to a [3 + 6] coordination. Another Ga atom (Ga2) is also nine-coordinate but has six near Mg neighbours and three Y at a somewhat longer distance in a [6 + 3] coordination. The Mg atom is tetrahedrally coordinated by four Ga atoms and has two additional Mg neighbours at a slightly longer distance. The site symmetries for Y, Ga1, Ga2 and Mg are m2m, , 2m and m2m, respectively. The crystal used was an inversion twin.

Large single crystals of the incongruently melting compound tribarium dichromium octaoxide, Ba₃Cr₂O₈, were grown by the traveling solvent floating-zone technique for the first time and characterized by X-ray diffraction at room temperature. The structure is composed of CrO₄³⁻ tetrahedra and Ba²⁺ ions. The chromium ions are found in the rare +5 valence state and form double-layered triangular lattices, which are stacked along the c axis with threefold periodicity. All atoms lie on special positions. One Ba, one O and the Cr atoms have site symmetry 3m, the other Ba atom has site symmetry m, and the other O atom has site symmetry m. Magnetic measurements suggest that this material is a spin dimer system with a spin-singlet ground state.

The lattice parameters and space group for dicerium pentathiosilicate, La₂SiS₅, have been reported previously [Michelet, Perez, Etienne & Darriet-Duale (1970.) C. R. Seances Acad. Sci. Ser. C271, 513–515]. Moreover, isotypism with the La₂GeS₅ structure (space group P2₁/c) has been assigned, but a structure refinement was not performed. The present single-crystal study reveals that the two independent La atoms are surrounded by 8 and 9 S atoms, forming bi- and tricapped trigonal prisms, respectively, whereas the Si atom has a slightly distorted tetrahedral coordination. The capped trigonal prisms are linked to tetrahedra via corners and edges; they are also connected to each other by sharing faces.

The title compound is built from edge-sharing centrosymmetric dimeric [Zr₂F₁₂]⁴⁻ complexes, HF molecules, Rb⁺ and K⁺ cations. Rubidium and potassium ions are statistically disordered on one of the metal positions. The Zr^IV coordination polyhedron is a monocapped trigonal prism. The two crystallographically independent Rb(K) ions are coordinated by F atoms and HF molecules with coordination numbers 7 and 9, respectively, for the two sites. In addition, the structure is stabilized by strong F—H...F hydrogen bonds.

Crystals of dipotassium iron(III) tin(IV) tris(orthophosphate) were grown from a self-flux in the system K₂O–P₂O₅–Fe₂O₃–SnO₂. The title compound is isotypic with the mineral langbeinite, K₂Mg₂(SO₄)₃. Its three-dimensional [M₂(PO₄)₃]_∞ framework is composed of [MO₆] (M = Sn, Fe) octahedra and [PO₄] tetrahedra interlinked via vertices. In comparison with the previous refinement from X-ray powder data [Aatiq, Haggouch, Bakri, Lakhdar & Saadoune. (2006). Powder Diffr. 21, 214–219], the present reinvestigation from single-crystal data allows a more precise determination of the distribution of the Fe and Sn atoms over two crystallographic positions and a revision of the P—O and M—O [M = K, (Fe, Sn)] bond lengths. For the two K⁺ cations, two different polyhedra with coordination numbers of 9 and 12 are observed. The (Fe, Sn) and K atoms are located on threefold axes.

Rb₂[IrF₆] possesses a framework structure constructed from Rb⁺ cations and [IrF₆]²⁻ complex anions. The cation is 12-coordinated by F atoms, forming a slightly distorted anticuboctahedron; the anion has the shape of an almost ideal octahedron. Rb, Ir and F atoms are located on special positions of 3m, m and m symmetry, respectively.

Cs₂[IrF₆] possesses a framework structure constructed from Cs⁺ cations and [IrF₆]²⁻ complex anions. The cation is 12-coordinated by F atoms, forming a slightly distorted anticuboctahedron; the anion has the shape of an almost ideal octahedron. Cs, Ir and F atoms are located on special positions of 3m, m and m symmetry, respectively.

The title compound, digallium(III) tris[tellurate(IV)] trihydrate, was obtained under hydrothermal conditions. It is isotypic with the analogous selenates(IV) of formula type M^III₂(SeO₃)₃(H₂O)₃ (M^III = Al, Cr, Fe, Sc, Ga) and comprises isolated GaO₆ and GaO₃(H₂O)₃ octahedra as well as TeO₃ trigonal pyramids as single building units. These polyhedra share corners and thereby establish a network structure. Additional hydrogen bonding between the water molecules and O atoms helps to stabilize this arrangement. Both crystallographically independent Ga atoms are located on threefold rotation axes. The crystal used was an inversion twin.

Potassium calcium diniobium hexaoxide fluoride, KCaNb₂O₆F, crystallizes in the cubic pyrochlore-type structure. In the crystal structure, NbO₆ octahedra are linked together by common corners to form a three-dimensional [Nb₂O₆]²⁻ network. (K,Ca) and F atoms, which are located in the voids of the [Nb₂O₆]²⁻ network, form zigzag [(K,Ca)F]²⁺ chains. The K and Ca atoms are distributed statistically over the same crystallographic position (site-occupancy factor = 0.5), having an eightfold coordination by six O atoms from the NbO₆ octahedra and by two F atoms. All atoms lie on special positions, viz. Nb has m, the (K,Ca) site has m, O has 2mm and F has 3m site symmetry.

In the title compound, [Sb(C₅H₈NS₂)₂Cl], the Sb^III ion is coordinated by the four S atoms belonging to two pyrrolidine-1-dithiocarboxylate ligands and a Cl atom in a distorted trigonal–bipyramidal geometry. The crystal structure is stabilized by intermolecular Sb...S interactions of 3.689 (1) Å.

In the title complex, [Ni(C₅H₃N₆)₂(H₂O)₂], the Ni^II atom is located in a general position and is coordinated by four N atoms from two 5-(pyrimidin-2-yl)tetrazolate ligands and O atoms of two water molecules in a distorted octahedral geometry. The bond distances and angles around the metal center lie in the ranges 2.051 (5)–2.097 (5) Å and 78.88 (19)–101.22 (19)°, respectively. The title complex is isostructural with its Mn^II and Cu^II analogues; it is, however, structurally different from an Ni^II complex obtained by direct reaction of 2-(1H-tetrazol-5-yl)pyrimidine with an Ni^II salt under hydrothermal conditions. In the crystal structure, molecules are linked together by O—H...N hydrogen bonds, forming a two-dimensional network parallel to the (001) plane.

The title compound, [Zn(C₈H₄O₄)(C₅H₆N₂)₂]_n, in the solid state comprises polymeric zigzag chains extending along the c axis. Each Zn^II ion is coordinated by two N [Zn—N = 1.991 (6) and 2.031 (5) Å] and two O [Zn—O = 1.912 (5) and 1.965 (5) Å] atoms in a distorted tetrahedral geometry. Weak C—H...O interactions contribute to the crystal packing stability.

In the solid state, the title compound, [Zn(C₈H₄O₄)(C₅H₈N₂)₂]_n, exhibits polymeric zigzag chains extended along th c axis. Each Zn^II ion is coordinated by two N and two O atoms in a distorted tetrahedral geometry. Weak C—H...O interactions contribute to the crystal packing stability.

In the crystal structure of the title compound, [Mn(C₅H₂N₂O₄)(C₁₀H₈N₂)(H₂O)]_n, the Mn atom is coordinated by three O atoms, two N atoms and one water molecule in a distorted octahedral geometry. Mn atoms are connected via the imidazole-4,5-dicarboxylate anions into chains, which are further connected by intermolecular N—H...O, O—H...N and O—H...O hydrogen bonding.

In the title compound, [Cd(C₁₄H₈O₄)(C₁₈H₁₀N₄)]_n, the Cd^II atom is coordinated by four O atoms from two different biphenyl-2,2′-dicarboxylate (bdc) dianions and two N atoms from the bidentate dipyrido[3,2-a:2′,3′-c]phenazine (L) ligand, resulting in a very distorted cis-CdN₂O₄ octahedral geometry. The Cd^II ions are bridged by the bdc ligands to form a one-dimensional chain structure. Neighboring chains interact through π–π interactions [centroid-to-centroid separation = 3.496 (3) Å], resulting in a two-dimensional supramolecular network.

In the title complex, [Sm(C₉H₁₀BN₆)(C₄₈H₃₆N₄)]·1.75C₇H₈, there are two independent complex molecules in the asymmetric unit, in each of which the Sm^III ion is coordinated by seven N atoms, four from a (4-methylphenyl)porphyrinate ligand and three from a hydridotris(pyrazol-1-yl)borate ligand, to form a capped trigonal-prismatic geometry. The Sm^III ion is `sandwiched' between two ligands and is located 1.2647 (13) and 1.2549 (14)Å from the porphyrin ring in the two complex molecules. The asymmetric unit also contains 3.5 molecules of toluene, the half-occupancy molecule being located close to a crystallographic inversion center. The porphyrin groups have `dome'-like geometries.

The title compound, [La₂(C₄H₄O₄)(C₈H₄O₄)₂]_n, was synthesized by hydrothermal methods. The La atom is coordinated by four O atoms from four benzene-1,4-dicarboxylate (BDC) ligands and four O atoms from three succinate anions, in a distorted square antiprismatic coordination geometry. The antiprisms are bridged by the benzene-1,4-dicarboxylate and succinate ligands, forming a three-dimensional network. The succinate ion is located on a centre of inversion.

The centrosymmetric title compound, [Ag₂Cd₂I₆(C₁₀H₈N₂)₄], was synthesized by the reaction of CdI₂, KAgI₂ and 2,2′-bipyridine in dimethylformamide. The crystal structure contains an Ag₂I₆ chain and Cd(2,2′-bipyridine)₂ units; the four 2,2′-bipyridine ligands are positioned at the ends of the molecule and μ₂-iodo bridges link two Cd(2,2′-bipyridine)I₂Ag units. The Cd atom exhibits a distorted octahedral geometry.

In the binuclear title complex, [Ag₂(C₉H₅O₆)₂(C₁₂H₉N₃)₂], the two Ag^I atoms are in a trigonal planar environment formed by two N atoms from two 2-(3-pyridyl)benzimidazole ligands and one O atom from a 3,5-dicarboxybenzoate ligand, forming a centrosymmetric cyclic dimer. Intermolecular N—H...O and O—H...O hydrogen-bonding interactions aggregate the binuclear units into a three-dimensional framework.

In the title molecule, [Fe(C₅H₅)(C₁₉H₁₅N₂)], the five-membered C₃N₂ imidazole ring forms dihedral angles of 84.71 (13) and 52.12 (11)°, respectively, with the substituted cyclopentadienyl and phenyl rings. In the crystal structure, in addition to a weak C—H...N interaction, there is a modest C—H...π(ring) interaction involving a C—H group of the unsubstituted cyclopentadienyl ring and the imidazole ring.

The title complex, [Ni(C₁₆H₁₃O₃)₂(H₂O)₄]·H₂O, is a transition metal complex of ketoprofen [2-(3-benzoylphenyl)propanoic acid], a well known non-steroidal anti-inflammatory drug. The asymmetric unit consists of half each of two complex molecules and one solvent water molecule. Both Ni^II atoms are located on crystallographic centres of inversion, each exhibiting an octahedral coordination geometry involving two carboxylate O atoms of different ketoprofenate ligands and four water molecules. A three-dimensional hydrogen-bonding framework is formed by O—H...O hydrogen-bonding interactions.

The title compound, {(C₅H₁₄N₂)[Cu₂Cl₄]}_n, was synthesized by the hydrothermal reaction of CuCl₂ with homochiral (R)-2-methylpiperazine. One Cu atom has a slightly distorted tetrahedral geometry defined by one terminal and three bridging Cl⁻ anions, while the other displays a trigonal planar geometry composed of one terminal and two bridging Cl⁻ anions. The crystal structure contains a polymeric anion forming a chain running along the a axis and (R)-2-methylpiperazinediium cations filling the space between these chains. Cations and anions are connected by hydrogen bonds.

The title compound, [Ag(C₈H₁₀NO₃S)(C₁₈H₁₅P)₂(H₂O)], has a mononuclear structure, where the Ag^I cation is four-coordinated by two triphenylphosphine ligands, one water molecule and the N atom of a 2-amino-4,5-dimethylbenzenesulfonate anion in a distorted tetrahedral AgP₂NO arrangement. A network of N—H...O and O—H...O hydrogen bonds helps to consolidate the packing.

The title compound, [Pd₂I₄(C₃₄H₂₄P₂)₂]·3CHCl₃, was obtained from the direct reaction of PdI₂ with 1,4-bis[(diphenylphosphanyl)ethynyl]benzene. The dimer complex molecule is centrosymmetric, with each Pd^II atom in a slightly distorted square-planar coordination geometry.

The Co^II ion in the title compound, [Co(C₅H₂N₂O₄)(H₂O)₄]·2.5H₂O, is chelated by the orotate dianion through carboxylate O and pyrimidine N atoms, and its octahedral geometry is completed by four water molecules. An intermolecular N—H...O hydrogen bond forms an orotate–orotate dimer. An extensive three-dimensional hydrogen-bonded network of O—H...O and N—H...O bonds and weak π–π interaction [3.754 (2) Å] stabilize the crystal structure. One of the solvent water molecules is located on a twofold rotation axis.

The title complex, {[Cd₃(C₄H₄O₄)₃(C₁₂H₈N₂)₃]·4H₂O}_n, has been isolated from the hydrothermal reaction of cadmium acetate with 1,10-phenanthroline (phen) and succinic acid. The structure features two-dimensional networks formed by succinate ligands bridging Cd atoms in two different coordination modes. A twofold rotation axis passes through one Cd atom. In one coordination mode, the Cd atoms are in a distorted octahedral CdO₄N₂ arrangement and the coordination atoms come from one phen ligand and two succinate ligands. In the other coordination mode, the Cd atoms are in the decahedral CdO₅N₂ geometries and the coordination atoms come from one phen ligand and three succinate ligands.

In the title compound, [Pb(C₄H₂O₄)(C₂₄H₁₆N₂)]_n, the Pb^II atom is chelated by 4,7-diphenyl-1,10-phenanthroline (L) and also bonded to four O atoms from two fumarate dianions to yield an irregular PbN₂O₄ coordination polyhedron. The centrosymmetric fumarate ligands bridge neighboring Pb^II atoms to generate a chain structure. Aromatic π–π stacking between L ligands in adjacent chains [minimum centroid–centroid separation = 3.462 (3) Å] leads to a two-dimensional supramolecular array.

The title compound, [La(C₈H₉)₃(C₉H₂₁N₃)], incorporating a fac-κ³N ligand and formed by reaction of La(CH₂C₆H₄-4-Me)₃(THF)₃ (THF is tetrahydrofuran) and 1,4,7-trimethyl-1,4,7-triazacyclononane (Me₃-TACN), was synthesized in THF solution. In the crystal structure, the La atom is seven-coordinated by three N atoms from a TACN ligand and four C atoms from three benzyl ligands, one of which is bound η².

In the title compound, [PdCl₂(C₁₅H₁₃N₃)], the Pd^II center is four-coordinated by two N-atom donors from one 1-benzyl-3-(2-pyridyl)-1H-pyrazole ligand and by two Cl atoms in a distorted square-planar coordination environment. In the crystal structure, adjacent Pd^II mononuclear units are linked to form dimers through C—H...π interactions. The dimers are further interlinked by weak intermolecular C—H...Cl interactions.

The title compound, [Cd₂(NO₃)₂(C₇H₇N₃O₃)₂](NO₃)₂, contains centrosymmetric dimeric cations in which two nitrate anions each serve as a bidentate ligand to one Cd atom and a bridge to the other. The other anion in the asymmetric unit (half the formula unit) is uncoordinated. The ligands form an atypical seven-coordinated augmented trigonal prism around the Cd^II atom, with a displacement from the centre of the polyhedron in the direction of the uncoordinated nitrate anion. The crystal structure displays numerous N—H...O hydrogen bonds.

In the title compound, [Cu(C₆H₅N₅)₂]_n, the Cu^II atom is coordinated by five N atoms from three distinct pyridyltetrazolate anions in a highly distorted square-pyramidal arrangement. The ligands link adjacent Cu^II atoms to form one-dimensional polymeric chains with a Cu...Cu separation of 6.224 (2) Å. The chains are further linked by π–π stacking interactions [centroid–centroid = 3.684 (2) Å and vertical distance = 3.281 (2) Å], forming a three-dimensional supramolecular framework.

The title compound, [Co(C₂H₃O₂)₂(C₁₂H₈N₂)]_n, is a polymeric complex involving bridging of Co^II ions by single syn-anti acetate ligands. Each Co atom is five-coordinated by two 1,10-phenanthroline N atoms and three O atoms of acetate ligands within a bipyramidal coordination geometry. In the crystal structure, C—H...O hydrogen bonds result in the formation of a polymeric ribbon structure.

In the crystal structure of the title compound, {[Ca(C₂H₅NO₂)₂(H₂O)₃]I₂}_n, there are two formula units per asymmetric unit; both calcium cations are sevenfold coordinated within irregular polyhedra. The polyhedra can be divided into two halves as square pyramidal and triangular prismatic due to the presence of one and two coordinated water molecules above and below the square plane. In all the glycine zwitterions, the amino groups form three two-centred hydrogen bonds, leading to a class I hydrogen-bonding pattern. The backbone conformations of the amino acids are cis and trans.

The title rare earth metal coordination polymer, [Er₂(C₁₄H₈O₄)₃(H₂O)₂]_n, has been synthesized through a hydrothermal reaction and characterized by thermogravimetric analysis and single-crystal X-ray diffraction. The Er^III ions both lie on crystallographic twofold rotation axes. There are one and a half organic ligands in the asymmetric unit. Both Er ions are coordinated by eight O atoms. Whereas one is bonded only to organic ligands, the other is also coordinated by two water molecules.

In the title compound, [Mg(C₂H₅NO₂)₂(H₂O)₄][Mg(H₂O)₆](SO₄)₂, the Mg^II atoms of both dications lie on inversion centres, and each of them is in an octahedral coordination environment. The glycine molecule exists in the zwitterionic form. The [Mg(H₂O)₆]²⁺ and [Mg(C₂H₅NO₂)₂(H₂O)₄]²⁺ dications pack as alternate layers parallel to the ab plane, with the sulfate anions lying between them. The ions are linked to form a three-dimensional network by O—H...O and N—H...O hydrogen bonds.

A new [Ni(imnt)₂]²⁻ salt (imnt²⁻ is 2,2-dicyanoethene-1,1-dithiolate) with a 1-benzyl-2-aminopyridinium [(Bz2NH₂py)⁺] cation, (C₁₂H₁₃N₂)₂[Ni(C₄N₂S₂)₂], was obtained by the direct reaction of NiCl₂·6H₂O, K₂imnt and (Bz2NH₂py)⁺·Br⁻ in water. The Ni^II ion lies on an inversion centre and the asymmetric unit contains a (Bz2NH₂py)⁺ cation and one-half of the Ni(imnt)₂²⁻ anion. The Ni^II ion adopts a square-planar coordination geometry. In the crystal structure, N—H...N and C—H...N hydrogen bonds are observed between the anions and the cations.

The title complex, (C₂₆H₂₁NP)₂[Ni(C₄N₂S₂)₂], is a salt of the mCNBzTPP⁺cation and the [Ni(mnt)₂]²⁻ anion [mCNBzTPP⁺ is the 1-(3-cyanobenzyltriphenylphosphonium) cation and mnt²⁻ is the maleonitriledithiolate anion] and was prepared by the direct reaction of NiCl₂, Na₂mnt and (mCNBzTPP)⁺·Br⁻ in ethanol. The asymmetric unit consists of two unique mCNBzTPP⁺cations and half each of two [Ni(mnt)₂]²⁻ anions with each Ni atom lying on an inversion centre. The Ni^II ions adopt a square-planar coordination geometry, binding to the S atoms of two mnt²⁻ ligands. Both [mCNBzTPP]⁺ cations adopt conformations in which their four aromatic rings are twisted with respect to the planes that include the P atoms and the two C atoms linking them to the 3-cyanobenzyl rings. Three weak C—H...N hydrogen bonds play an important role in stabilizing the crystal structure.

The title cocrystal, [Mn(C₁₉H₂₀N₂O₂)(C₅H₅N)(CH₃OH)]PF₆·[Mn(C₁₈H₁₈N₂O₂)(C₅H₅N)(CH₃OH)]PF₆, is a 1:1 co-crystal of two Mn^III complexes with Schiff base ligands. In each structure, the Mn^III centre is in a six-coordinate distorted octahedral N₃O₃ environment, with the N₂O₂ donor atoms of the tetradentate Schiff base ligand as the equatorial plane and the pyridine and methanol molecules in the two axial positions. The difference in the two components of the co-crystal, which are disordered over the same site, is the addition of a methyl group to one of the two methylene C atoms linking the imine N atoms of the Schiff base ligand in one component. In the crystal structure, intermolecular O—H...O hydrogen bonds and weak intermolecular C—H...O interactions link the molecules into a network. A weak C—H...N intramolecular interaction is also observed in the structure of [Mn(C₁₉H₂₀N₂O₂)(C₅H₅N)(CH₃OH)]PF₆.

In the title complex, [Cd(H₂O)₆](C₉H₇N₄O₃S)₂, the metal center is six-coordinate, forming an ideal centrosymmetric octahedral geometry. A three-dimensional supramolecular architecture is formed through hydrogen-bonding (O—H...O) and offset π–π stacking interactions (distance between pairs of adjacent benzene rings = 3.532 Å and centroid-to-centroid separation = 3.672 Å).

The title compound, {(C₁₀H₁₀N₂)[Cu₂(C₅HN₂O₄)₂]}_n, has been synthesized under hydrothermal conditions. The self-assembly of the pyrazole-3,5-dicarboxylate ligands and Cu^II atoms results in a one-dimensional anionic chain, in which the Cu^II atom is five-coordinate in a square-pyramidal geometry. The doubly protonated 4,4′-bipyridine (bpy) cation lies on an inversion center. A two-dimensional supramolecular network is formed through N—H...O hydrogen bonds between the bpy cations and the uncoordinated carboxylate O atoms of the polymeric anions. The dinuclear repeat unit with two bridging pyrazole rings is centrosymmetric.

In the title compound, [Ag₂(C₈H₁₀NO₃S)₂(H₂O)₄], each Ag^I atom is coordinated by three water molecules and one N atom from a 2-amino-4,5-dimethylbenzenesulfonate ligand in a severely distorted tetrahedral geometry. The two Ag^I atoms are bridged by two water molecules, forming a centrosymmetric binuclear complex. The distance of 3.615 (9) Å between the two Ag^I atoms suggests that there are no Ag...Ag interaction within the binuclear molecule.

The asymmetric unit of the title structure, {[Ag(C₁₈H₁₆N₂O₂)(C₄H₂O₄)_0.5]·H₂O}_n, contains one Ag^I cation, one 1,4-bis(3-pyridylmethoxy)benzene (L) ligand, half of a fumarate ligand and one solvent water molecule. The Ag^I ion is in a distorted tetrahedral coordination geometry. Each L ligand bridges two symmetry-related Ag^I cations to form extended one-dimensional chains, which are, in turn, bridged by fumarate ligands to create chains of rings. The solvent water molecules donate hydrogen bonds to the carboxylate O atoms of fumarate ligands, generating a two-dimensional supramolecular structure.

In the molecule of the title complex, [V(NCS)₂(C₅H₅N)₄], the V^II atom, located on a centre of inversion, is coordinated in a distorted octahedral arrangement by two N atoms of two SCN⁻ and four N atoms of four pyridine ligands. In the crystal structure, C—H...N hydrogen bonds result in the formation of a supramolecular network.

The asymmetric unit of the title compound, [Ni(H₂O)₆](C₆H₆NO₃S)₂, contains one half-cation and one anion; the Ni atom lies on an inversion centre. In the crystal structure, intermolecular O—H...O and O—H...S hydrogen bonds result in the formation of a supramolecular network. The conformation of the anion is stabilized by an intramolecular C—H...O hydrogen-bonding interaction.

The crystal structure of the low-temperature phase of diethylammonium tetrachloridocuprate(II), (C₄H₁₂N)₂[CuCl₄], has been determined by Simonsen & Harlow [(1977). Am. Crystallogr. Assoc. Ser. 2 Vol. 5, No. 1, Abstract HN5], but no atomic coordinates are available. We therefore redetermined the structure at 100 K. It comprises three crystallographically independent formula units linked by hydrogen bonds into a two-dimensional network. One tetrachloridocuprate(II) anion is virtually square-planar while the two others are tetrahedrally distorted.

The molecule of the title compound, [SnCl₂(C₅H₉O₂)₂], has crystallographic twofold symmetry with the Sn atom lying on the rotation axis. The Sn atom is in a distorted SnC₂Cl₂O₂ octahedral geometry with two five-membered chelate rings formed by intramolecular Sn—O interactions [2.551 (2) Å]. The pendant ethyl group is disordered over two positions in a 0.695 (12):0.305 (12) ratio.

The previous structure report [Howie & McQuillan (1986). J. Chem. Soc. Dalton Trans. pp. 759–764] of the title compound, [Mo(C₁₀H₈N₂)(C₁₀H₉N₃)(CO)₃], has been corrected. In the present structure, the precision of the Mo—C and Mo—N bond distances for the fac-MoC₃N₃ centre are significantly improved, and an N atom and a C—H group have been exchanged. Possible intramolecular N—H...C and C—H...N and intermolecular C—H...O interactions are described.

The title compound, [Ni(C₇H₃NO₄)(H₂O)₄]·H₂O, synthesized by reaction of nickel(II) nitrate hexahydrate with pyridine-2,5-dicarboxylic acid and piperazine in water. It has essentially the same structure with the analogous nickel(II) dihydrate complex [Shiu, Chen, Liao & Wang (2003). Acta Cryst. E59, m1072–m1074]. The compound contains a six-coordinate Ni^II ion, which is bonded to the N and an O atom of the carboxylate group in the 2-position of the pyridine-2,5-dicarboxylate ligand, and four water O atoms. The Ni^II^ atom has a distorted octahedral coordination environment. Intermolecular hydrogen-bonding interactions are present, linking the nickel(II) complex and water molecules in the crystal structure.

The asymmetric unit of the title compound, (C₄H₁₂N₂)[Fe(C₇H₃NO₄)₂]₂·H₂O or (pipzH₂)²⁺·2[Fe(pydc)₂]⁻·H₂O (pipz is piperazine and pydcH₂ is pyridine-2,6-dicarboxylic acid), contains one dication, two anions and one uncoordinated water molecule. In the anions, each Fe^III ion is hexacoordinated by four O [Fe—O = 2.005 (2)–2.044 (2) Å] and two N [Fe—N = 2.050 (2)–2.075 (2) Å] atoms in a distorted octahedral geometry. An extensive three-dimensional network formed by classical O—H...O and N—H...O and weak C—H...O intermolecular hydrogen bonds stabilizes the crystal packing, which also exhibits π–π [centroid–centroid distances 3.500 (2)–3.533 (2) Å] and C—H...π interactions.

The title compound, [Eu₂(C₄H₄O₄)(C₈H₄O₄)₂]_n, has been synthesized by hydrothermal methods. The Eu atom is coordinated by four O atoms from four benzene-1,4-dicarboxylate (BDC) anions and four O atoms from three succinate anions in a distorted square antiprismatic coordination geometry. The antiprisms are bridged by the benzene-1,4-dicarboxylate and succinate anions into a three-dimensional coordination network. The succinate anions are located on centres of inversion.

The title compound, [Sm₂(C₄H₄O₄)(C₈H₄O₄)₂]_n, has been hydrothermally synthesized. The Sm atom is coordinated by four O atoms from four benzene-1,4-dicarboxylate (BDC) ligands and four O atoms from three succinate anions in a distorted square antiprismatic geometry. The antiprisms are bridged by the BDC and succinate ligands, forming a three-dimensional network. The succinate ion is located on a centre of inversion.

The title dinuclear complex, [Sn₂(CH₃)₄(C₇H₃NO₄)₂(H₂O)₂], lies on a crystallographic inversion center. The unique Sn^IV atom is coordinated in a slightly disorted pentagonal-bipyramidal geometry. The two symmetry-related Sn^IV atoms are connected via two asymmetric Sn—O—Sn bridges (Sn—O = 2.473 and 2.634 Å), such that an exactly planar Sn—O—Sn—O ring is formed.

In the title complex, {[Tb(C₂O₄)_1.5(H₂O)₃]·CH₃OH}_n, each Tb^III atom is coordinated by six O atoms from three oxalate ligands and three water molecules, and displays a tricapped–trigonal prismatic geometry. The oxalate groups link the metal ions, forming layers perpendicular to the c axis that can be described via topological analysis as a three-connected (6³) sheet. O—H...O hydrogen bonds from the water and methanol molecules to the oxalate ions further interconnect the layers, forming a supramolecular network.

In the title compound, [Zn(C₁₁H₁₀N₃O₂)₂]·3H₂O, the Zn^II atom is coordinated by four N and two O atoms in a distorted octahedral geometry. One water molecule is disordered equally over two positions.

The title compound, [Cd(C₆H₆N₄)₃]CO₃, is composed of discrete cations and anions, which are each located on a twofold rotation axis. The central Cd^II ion exhibits a distorted octahedral geometry and is coordinated by six N atoms from three 2,2′-biimidazole molecules. The crystal packing is stabilized by N—H...O hydrogen bonds.

The title complex, [Cu(C₇H₂N₂O₇)(C₄H₈N₂O₂)(H₂O)], is a mononuclear copper(II) compound. The Cu^II ion is five-coordinated in a distorted pyramidal geometry by two N atoms from one dimethylglyoxime molecule, two O atoms from one 3,5-dinitro-2-oxidobenzoate ligand and one O atom from a water molecule. Strong hydrogen bonds connect adjacent molecules into a three-dimensional network.

In the title compound, [ZnCl₂(C₂₀H₂₅N₃O₄)]·0.5H₂O, the Zn^II ion assumes a trigonal bipyramidal coordination geometry formed by a tridentate amine ligand and two Cl⁻ anions. The tridentate amine ligand chelates the Zn^II ion in a meridional configuration. The extensive hydrogen-bonding network helps to stabilize the crystal structure.

In the title compound, [Zn(C₆H₈N₂)₃(H₂O)](C₇H₇SO₃)₂·3H₂O, the Zn atom has a slightly tetragonally distorted octahedral geometry, with four shorter equatorial Zn—N and Zn—O bonds [2.153 (4)–2.189 (3) Å] and two longer axial Zn—N bonds [2.239 (4) and 2.243 (4) Å]. The crystal packing is stabilized by weak intermolecular N—H...O hydrogen bonds.

In the title compound, [Mo₂(C₂H₄NO₂)₂O₂S₂(C₂H₅NO₂)], the two Mo^V atoms are bridged by two μ₂-S atoms and one glycine ligand in an O:O′-bidentate mode. In addition, each Mo^V atom is bonded to one terminal oxygen ligand and chelated by one N,O-bidentate glycinate ligand, resulting in a distorted octahedral coordination. A complex hydrogen-bonding network is constructed by intermolecular N—H...O hydrogen bonds.

In the title compound, tetrakis[μ₃-2-(5-hydroxy-2-oxidobenzylideneamino)-2-methylpropanolato]tetracopper(II) methanol tetrasolvate, [Cu₄(C₁₁H₁₃NO₃)₄]·4CH₃OH, two Cu₂ cores are linked by two μ₃-bridging alkoxo O atoms to form a centrosymmetric dimer of dicopper(II) units. Two Cu atoms coordinate to the NO₂ (a phenolic O atom, an alcoholic O atom and an imine N atom) chelator unit of one ligand and an alcohol O atom of the other ligand, forming a distorted planar coordination configure. The remaining Cu atoms coordinate in a pyramidal geometry. The distorted basal plane is also formed by the N₂O unit and the alcohol O atom from the second ligand, while an alcohol O atom from a third ligand occupies the axial position.

The title complex, [CuCl(C₂₀H₁₈N₄O₄)(C₁₈H₁₅P)], has two molecules in the asymmetric unit. The Cu atom is four-coordinate in a distorted tetrahedral geometry, bonded to two imine N atoms of the Schiff base, Cl and PPh₃; the main distortion is the small bite angle of the chelating Schiff base ligand. One triphenylphospine ligand adopts an approximate propeller conformation, with dihedral angles of 69.36 (14), 77.02 (12) and 82.44 (15)° for pairs of benzene rings, the normals of which make angles of 37.8, 65.4 and 72.6° with the P—Cu bond; the arrangement in the other triphenylphosphine ligand is rather less symmetrical, with dihedral angles of 63.41 (15), 70.67 (12) and 78.11 (12)° and angles of 20.3, 78.6 and 83.2° between the ring plane normals and the P—Cu bond. There are intermolecular C—H...Cl and C—H...O interactions. The crystal was a non-merohedral twin, with approximately equal contributions of the two domains.

The title complex, [Mo₂(CH₃O)₆(NO)₂(H₂O)₂], is a pseudocentrosymmetric dimer. The Mo^II centres are bridged by two methoxo groups and adopt distorted octahedral geometries. The crystal structure exhibits two intramolecular O—H...O contacts (O...O < 3.0 Å) between coordinated water molecules and methoxo groups. One H atom of each water molecule is disordered equally over two sites.

The Cu^II atom (site symmetry ) in the title compound, [Cu(C₁₃H₁₀ClN₂O₃S)(C₁₃H₁₁N₂O₃S)], is N,O-chelated by the monoanionic ligands in a trans-CuN₂O₂ square-planar geometry. The 2′-(2-oxidobenzylidene)benzenesulfonohydrazide anion is disordered equallywith the chlorine-substituted 2′-(5-chloro-2-oxidobenzylidene)benzenesulfonohydrazide anion. An intermolecular N—H...O hydrogen bond helps to stabilize the crystal structure.

The 3-(4-carboxylatophenoxy)propionate dianion in the title compound, [Cd₂(C₁₀H₈O₅)₂(C₁₀H₈N₂)₂]·C₇H₆O₃·H₂O, links adjacent metal atoms into a chain, the dianion chelating through both O atoms of its two –CO₂⁻ end groups. One of the carboxylate O atoms (that belonging to the aliphatic carboxylate end) engages in interchain coordination, linking two chains into a ribbon. The ribbons are linked to the disordered water molecule and 4-hydroxybenzoic acid by O—H...O hydrogen bonds, further consolidating the ribbon motif. The Cd^II atom exists in a seven-coordinate CdN₂O₅ enviroment that approximates to a monocapped octahedron. The dinuclear repeat unit is centrosymmetric.

The centrosymmetric trinuclear title compound, [Zn₃(C₂H₃O₂)₂(C₇H₅O₃)₄(C₁₂H₈N₂)₂], has six carboxylate groups each bridging two metal centers. The Zn atom on a center of inversion is coordinated by six O atoms in an octahedral environment. The other Zn atoms are each chelated by the N-heterocycle, and their coordination number is also six as the acetate group also functions as a chelating group. The hydroxy group of one of the two symmetry-independent salicylate groups is disordered over two positions in a 2:1 ratio.

In the crystal structure of the title compound, [Zn₃(C₁₁H₇O₈)₂(H₂O)₁₀]·2H₂O, the trianionic carboxylate unit uses one oxyacetate –OCH₂CO₂⁻ arm to chelate a Zn atom through the ether and carboxylate O atoms. The other oxyacetate arm is free; the –CO₂⁻ end has a formal negative charge. The central Zn atom lies on a special position of site symmetry . The uncoordinated water molecules form a three-dimensional hydrogen-bonded network. One solvent water molecule is disordered over two positions in a 2:1 ratio.

The title compound, {[Zn₂(C₂HN₉)₂(H₂O)₆][Zn₂(C₂HN₉)₂(H₂O)₆]·2H₂O}_n, consists of one dinuclear [Zn(C₂HN₉)(H₂O)₃]₂ molecule, in which the two C₂HN₉⁻ monoanions each N,N′-chelate a [Zn(H₂O)₃] unit while using a third N atom to bind to the other triaquazinc unit. In the second [Zn(C₂HN₉)(H₂O)₃] unit, the monoanion similarly N,N′-chelates a triaquazinc unit, but the bridging interaction furnishes a zigzag chain structure. For both Zn centres, a mer-ZnN₃O₃ octahedral coordination arises. A network of N—H...N, O—H...N and O—H...O hydrogen bonds helps to establish the structure.

The title compound, [Ni(C₁₃H₂₀N₂O₂)₂(H₂O)₂](NO₃)₂·2H₂O, consists of a mononuclear nickel(II) complex, two nitrate anions and two solvent water molecules. The Ni atom lies on an inversion centre and is chelated by the phenolic O and imine N atoms from two Schiff base ligands, and coordinated by the O atoms from two water molecules, giving a slightly distorted octahedral geometry. Within the crystal structure, the components form chains parallel to the a axis by intermolecular N—H...O, O—H...O and O—H...N hydrogen bonds.

In the centrosymmetric title complex, [Cd(C₇H₄NO₃S)₂(C₄H₁₁NO)₂], the Cd^II ion is coordinated by two saccharinate (sac) anions and two N,O-bidentate 2-(ethylamino)ethanol ligands, displaying a distorted octahedral coordination. Pairs of molecules are doubly bridged by O—H...O hydrogen bonds and these dimers are further linked by weak C—H...π(sac) interactions.

In the title compound, [Mn(C₁₄H₈N₂O₆)(H₂O)₄]_n, each 6,6′-dihydroxy-3,3′-diazenediyldibenzoate ligand acts as a carboxylate bridge, leading to the formation of polymeric chains running in the [110] direction. The Mn atom is hexacoordinated in a distorted octahedral geometry by six O atoms from two ligands and four water molecules [Mn—O = 2.1379 (16)–2.2082 (15) Å]. The crystal packing is stabilized by π–π interactions [centroid-to-centroid distances 3.830 (16) and 4.476 (17) Å] and intermolecular O—H...O and O—H...N hydrogen bonds.

The title complex, [Ni₂(C₂H₃O₂)₄(C₁₀H₇N₃)]_n or [Ni₂(dbp)(C₂O₂H₃)₄]_n (dbp = 2,3′-dipyridylamine), forms a polymeric linear chain. The repeat unit of the chain is the dinuclear [Ni₂(C₁₀H₇N₃)(C₂O₂H₃)₄] of the paddle-wheel type. The two Ni atoms are related by symmetry through an inversion center. Each Ni atom has a square-pyramidal coordination environment, with four O atoms from four acetate groups forming the basal plane, and a pyridyl N atom occupying the apex. The bridging dbp ligand is disordered over an inversion center, involving two alternative positions for the NH group.

In the crystal structure of the title compound, [Ag(NO₃)(C₁₄H₁₂N₂O₂)], the Ag^I centre is three-coordinated by two N atoms from 2,9-dimethoxy-1,10-phenanthroline and one O atom of the nitrate anion. The Ag—N bond lengths are almost identical, and O—Ag—N bond angles are larger than the bite angle N—Ag—N. In the main ligand, the O and C atoms of the methoxy groups lie almost in the plane defined by the phenanthroline ring system. Based on the extended delocalized π system of phenanthroline and the d¹⁰ electronic configuration of the metal centre, the title complex is expected to produce strong luminescent emission when properly excited.

The asymmetric unit of the title compound, [Ag(C₉H₇N₂)]_n, contains two independent Ag^I ions and two 2-phenylimidazolate (L) ligands. Each Ag^I centre is linearly coordinated by two N atoms [Ag—N 2.092 (3)–2.097 (3) Å]. Ligands L bridge Ag^I ions into polymeric chains parallel to the c axis, with Ag...Ag separations of 6.232 (2) and 6.254 (2) Å. No interactions between the Ag centres from neighbouring chains are observed.

The asymmetric unit of the title compound, [Cd(C₇H₄NO₃S)₂(C₈H₂₂N₄)]·0.25H₂O, consists of two [Cd(sac)₂(paen)] molecules [sac is saccharinate (C₇H₄NO₃S) and paen is N,N′-bis(3-propylamine)ethylenediamine (C₈H₂₂N₄)], and a partial- occupancy water molecule. Each Cd^II ion is octahedrally coordinated. The equatorial plane of the octahedron is formed by N atoms of the paen ligands, and the axial positions are occupied by the N atoms of the sac ligands. In one of the molecules, the sulfonyl group of a sac ligand is disordered over two different orientations, with site-occupancy factors of 0.83 and 0.17. N—H...O hydrogen bonding is observed between the independent molecules. Neighbouring [Cd(sac)₂(paen)] units are linked by N—H...O hydrogen bonds into chains running parallel to the a axis.

The title compound, [Sn(C₆H₅)₃(C₇H₄BrO₃)], crystallizes with two independent molecules in the asymmetric unit, the molecular conformations of which are almost identical. In each molecule, the Sn atom is coordinated by one O and three C atoms in a distorted tetrahedral geometry [Sn—O = 2.045 (4) and 2.087 (4) Å; Sn—C = 2.082 (7)–2.117 (7)Å]. The hydroxy groups are involved in intramolecular O—H...O hydrogen bonds.

The title compound, [Cd(C₁₃H₉ClNO₃)₂(H₂O)₂], is a mononuclear complex in which the Cd^II atom, located on a twofold axis, shows an octahedral coordination geometry. It is surrounded by four carboxylate O atoms from two 4-[(6-chloropyridin-3-yl)methoxy]benzoate acid ligands and two water molecules. O—H...O hydrogen bonds link these complexes to generate a two-dimensional supramolecular network.

The title compound, (C₁₇H₂₁N₂)₂[Cu₂I₄], consists of an organic cation, 4-[4-(dimethylamino)stryl]-1-ethylpyrdinium, and an inorganic anion, [Cu₂I₄]²⁻. The Cu(I) atom exhibits a trigonal coordination. The anions form discrete centrosymmetric dimers about inversion centers and are surrounded by the cations.

The title compound, [Sn(CH₃)₃(C₆H₅O₂S)]_n, has an infinite chain structure. The SnO₂C₃ centre has a slightly distorted trigonal bipyramidal geometry with the O atoms in the axial positions.

In the title complex, [Sn(C₆H₅)₃(C₈H₇N₄S)], all bond lengths and angles show normal values. The Sn centre is four-coordinated by three C atoms [Sn—C 2.119 (6)–2.133 (6) Å] and one N atom [Sn—N 2.107 (5) Å] in a distorted tetrahedral geometry. The crystal packing exhibits no classical intermolecular hydrogen bonds.

In the title compound, [Cu(C₁₁H₁₄BrN₂O)(NCS)], the Cu atom is four-coordinated by the NNO donor set of the Schiff base ligand and by the terminal N atom of the thiocyanate anion, forming a square-planar geometry. An N—H...S hydrogen bond helps to establish the packing.

In the title complex, [Fe₂(C₁₅H₁₆N₄O)₂]·2H₂O, two ferrocene units are bridged by two Schiff base linkers. This molecule lies on an inversion centre, and the asymmetric unit also contains a solvent water molecule. In the crystal structure, complexes and water molecules are connected through weak N—H...O, O—H...O, O—H...N and N—H...N hydrogen bonds.

In the molecule of the title compound, [Cu(C₄H₄O₅)(C₇H₅N₃O₂)(H₂O)], the Cu^II atom is coordinated by one tridentate oxydiacetate (ODA) dianion, one monodentate nitrobenzimidazole (NBZIM) molecule and one H₂O molecule, in a distorted square-based pyramidal geometry. In the crystal structure, O—H...O, N—H...O and C—H...O hydrogen bonds link the molecules, forming a three-dimensional network. π–π Stacking interactions between parallel NBZIM rings consolidate the supramolecular structure [the shortest interplanar distances are 3.360 (3) and 3.269 (3) Å].

The title compound, [Ag₂(C₆H₄O₆S₂)(C₁₂H₉N₃)₂]_n, is a coordination polymer prepared by a hydrothermal reaction. Two Ag^I atoms are connected by two 2-(3-pyridyl)benzimidazole ligands, resulting in a binuclear macrocycle. The bridging benzene-1,4-disulfonate ligands link the binuclear units, forming a chain. The crystal packing is stabilized by N—H...O hydrogen bonds.

In the crystal structure of the title compound, [Zn₂(C₁₆H₁₈FN₃O₃)₂(C₉H₄O₆)₂]·6H₂O, the Zn^II atoms are each coordinated by five O atoms within a distorted trigonal biyramid. The two Zn^II atoms are connected by two symmetry-related carboxylate O atoms into dimers, which are located on centres of inversion. These dimers are linked by N—H...O and O—H...O hydrogen bonding.

The title coordination polymer, [[Fe(C₄H₄O₅)(H₂O)₂]·H₂O]_n, was obtained by the hydrothermal reaction of FeSO₄ with malic acid in alkaline aqueous solution. Each Fe^II atom is coordinated by four O atoms from three malate ligands and two water molecules, and displays a distorted octahedral geometry. The polychelated malate ligands bridge Fe ions to form corrugated layers; these layers are further assembled by intermolecular O—H...O hydrogen-bonding interactions to form a three-dimensional supramolecular network, with channels running along the b axis in which the uncoordinated water molecules are located. The solvent water molecule is disordered over two positions, with occupancy ratios of 0.78/0.22.

The title compound, {[Ag(C₇H₈N₄)]PF₆}_n, has a one-dimensional zigzag chain structure. The Ag⁺ cation and the PF₆⁻ anion reside on crystallographic inversion centres. The Ag⁺ cation is coordinated by the unsubstituted N atoms of two separate 1,1′-methylenediimidazole ligands. The closest Ag...Ag separation in the same cationic chain is 7.704 (2) Å and the dihedral angle between the two imidazole rings in the same ligand is 85.5 (1)°. A two-dimensional layer framework is formed by weak Ag...N interactions between adjacent chains, with an Ag...N distance of 3.472 (2) Å.

In the title complex, [Rh(C₁₃H₉NOF)₂Cl(C₁₈H₁₅P)], the two 2-(4-fluorophenylamino)troponate groups chelate the Rh^III atom and the four coordinating atoms are disposed around it as a square in a trans manner. The Cl and P atoms occupy axial positions of the octahedral coordination geometry. The crystal structure shows weak intra- and intermolecular interactions.

The title compound, (C₁₈H₂₃N₂)[AgI₂], contains linear anions. In the crystal structure, weak nonclassical C—H...I hydrogen bonds link adjacent cations and anions.

The title compound, [Ni(C₂H₃N)₃(C₉H₂₃N₃)](PF₆)₂, has the Ni atom in an octahedral environment. It is coordinated by the three N atoms of one chelating 1,1,4,7,7-pentamethyldiethylenetriamine molecule and by three acetonitrile molecules. The charge is balanced by two hexafluoridophosphate anions. The ethylene chains and the central methyl group of the 1,1,4,7,7-pentamethyldiethylenetriamine are disordered over two sites with occupation factors 0.619 (6) and 0.381 (6).

The title compound, [Cr(C₄H₁₀O₂)(C₁₂H₂₇O₃SSi)₂], is a molecular chromium(II) thiolate that has the 1,2-dimethoxyethane ligand coordinating through one of its two O atoms. The metal is O,S-chelated by the thiolate anion, and the O atom from the 1,2-dimethoxyethane ligand occupies the apical position of the square-pyramidal coodination geometry. The asymmetric unit contains two molecules. Three C atoms of one ^tBu group are disordered approximately equally over two positions. One C atom of another ^tBu group is disordered over two positions, with site occupancies of ca. 0.6 and 0.4.

In the title compound, [Pd(C₉H₁₇N₂O₃S)Cl]·1.5H₂O, the Pd atom is tetracoordinated by a naphthyl C, a diazene N, a Cl and a sulfonyl O atom in an approximate square-planar geometry; the asymmetric unit also contains 1.5 molecules of water, one molecule lying on a twofold rotation axis. A hydrophilic environment wrapping the polar portion of the compound is created by an array of water molecules. The crystal packing is stabilized by an intermolecular C—H...O interaction and eight intermolecular π–π interactions; the centroid–centroid distances range from 3.647 (2)–3.8098 (18) Å, with perpendicular interplanar distances between 3.169 and 3.590 Å.

Single crystals of the title compound, [Co(NO₃)(C₁₀H₈N₂)₂](OH)(NO₃)·4H₂O, were obtained from a Co²⁺–2,2′-bipyridine–CrO₄²⁻ mixture as the second crystalline product. The present single-crystal study confirms a previous refinement [Reimann, Zocchi, Mighell & Santoro (1971). Acta Cryst. B27, 2211–2218], and also includes all H-atom positions, which were identified from a difference map. The structure displays an O—H...O hydrogen-bonding network between the non-coordinated nitrate group, the hydroxide anion and the water molecules, forming a framework around the distorted octahedral Co complex. A twofold rotation axis passes through Co and the nitrato ligand.

In the crystal structure of the title compound, [Ni(C₂H₄NO)(NO₃)(C₁₂H₈N₂)]_n, the Ni^II atoms are linked by acetamidate ligands to form a chain. Each Ni^II atom is five-coordinated by two N atoms of a 1,10-phenanthroline ligand, one nitrate O atom, and one N and one O atom of acetamide within a bipyramidal coordination geometry. In the crystal structure, the chains are linked by hydrogen bonds into a polymeric ribbon structure.

The title compound, [Cu(C₂H₃O₂)₂(C₁₂H₈N₂)]_n, is a polymeric complex involving bridging of Cu^II ions by single syn–anti acetate ligands. Each Cu atom is five-coordinated by two 1,10-phenanthroline N atoms and three O atoms of acetate ligands in a distorted square-pyramidal geometry. In the crystal structure, C—H...O hydrogen bonds result in the formation of a polymeric ribbon structure.

The new title nickel(II) complex, (C₁₆H₁₃BrN)₂[Ni(C₄N₂S₂)₂], is a salt obtained by the direct reaction of NiCl₂, disodium maleonitriledithiolate (Na₂mnt) and 1-(4-bromobenzyl)isoquinolinium bromide, (BrBzIQl)⁺Br⁻, in methanol. The structure contains two (BrBzIQl)⁺ cations and an Ni(mnt)₂²⁻ anion in the asymmetric unit. In the two (BrBzIQl)⁺ cations, the dihedral angles between the benzene ring and the isoquinoline plane are 71.0 (4) and 82.1 (4)°. The [Ni(mnt)₂]²⁻ anion exhibits a slightly distorted square-planar coordination geometry. The crystal structure is stabilized by three weak C—H...N hydrogen bonds and a π–π stacking interaction involving the benzene ring and isoquinoline plane [centroid–centroid separation 3.774 (2) Å]

The title compound, [Cd₂Cl₄(C₁₂H₉N₃)₂], was prepared under hydrothermal conditions. In the centrosymmetric dimeric molecule, two Cd^II atoms are bridged by two Cl atoms. One terminal Cl atom and two N atoms from a bidentate chelating 2-(2-pyridyl)benzimidazole ligand complete a distorted square-pyramidal geometry around each Cd^II atom. A three-dimensional network is constructed via intermolecular N—H...Cl and weak C—H...Cl hydrogen bonds, as well as π–π interactions between adjacent ligands with a centroid-to-centroid distance of 3.49 (1) Å between the benzimidazolyl and pyridyl groups and a centroid-to-centroid distance of 3.54 (1) Å between the imidazolyl rings.

The title compound, [Cu(C₁₂H₁₆N₃O₃)(CH₃COO)]_n or [Cu(CMP)(CH₃COO)]_n {CMP is 2-[3-(dimethylamino)propyliminomethyl]-4-nitrophenol}, was synthesized by the reaction of 2-hydroxy-5-nitrobenzaldehyde, N,N-dimethylpropane-1,3-diamine and copper(II) acetate monohydrate in a methanol solution. The compound is an acetate-bridged polymeric copper(II) complex. The Cu^II atom is coordinated in a square-pyramidal manner by one Schiff base CMP ligand and two acetate anions. The Schiff base molecule acts as a tridentate ligand, coordinating the Cu^II ion through its phenolate O atom, imine N atom and amine N atom. The acetate anion acts as a bridging group, coordinating two adjacent Cu^II ions through its two O atoms, one in the basal plane and the other in the apical position. The [Cu(CMP)] units are linked through the bridging acetate groups, forming chains running along the c axis.

One naphthalene-1,4-dicarboxylate dianion in the title compound, [Cu₂(C₁₂H₆O₄)₂(C₁₄H₈N₄)₂]·4H₂O, bridges two N-heterocycle-chelated Cu atoms whereas the other one bridges four N-heterocycle-chelated Cu atoms, linking them into a flat carboxylate-bridged layer. The two independent Cu atoms show square-pyramidal coordination. Water molecules occupy the space between adjacent layers; they are possibly disordered, and their H atoms were not located.

The benzenetetracarboxylate tetraanion in the title compound, [Zn₂(C₈H₂O₈)(H₂O)₄]_n, lies on a center of inversion. Two delocalized carboxylate –CO₂ groups are each connected to two different diaquazinc units, whereas the other two localized carboxylate –CO₂ are each bonded to one different diaquazinc unit. The metal atom is five-coordinate as a consequence of such μ₆-bridging; the water molecules occupy an axial and an equatorial site of the trigonal bipyramid in the three-dimensional network. The architecture is further consolidated by extensive hydrogen bonding in which one water molecule serves as a donor and the other as both a donor and an acceptor.

The three terephthalate groups in the title polymeric coordination compound, {(C₂H₈N)[NaZn₂(C₈H₄O₄)₃(C₂H₇N)₂]}_n, lie on inversion centers. One functions as a bridge to two Na and two Zn atoms. The O atoms of the other two terephthalate groups bind to only one Zn atom. The Zn atom is additionally coordinated by a dimethylamine molecule; together with bonding from the O atoms of the three terephthalate groups, the geometry is tetrahedral. The manner of bridging of the terephalate groups gives rise to a polyanionic honeycomb sheet motif; the sheets are held into a three-dimensional network through the Na atoms. The cavities in the network are occupied by the dimethylammonium cations. The organic cation is disordered about a centre of inversion.

In the title compound, [Sb(C₅H₈NOS₂)₃], the Sb^III ion adopts a distorted pentagonal–pyramidal geometry because of its stereochemically active lone pair of electrons. In the crystal structure, the molecules are associated into dimers by short intermolecular Sb...S contacts [3.4111 (17) Å].

The asymmetric unit of the title compound, [Zn(H₂O)₆](C₆H₆NO₃S)₂, contains one half-cation and one anion; the Zn atom lies on an inversion centre. In the crystal structure, intermolecular O—H...O and O—H...S hydrogen bonds result in the formation of a supramolecular network; an intramolecular C—H...O hydrogen bond is also present.

In the title compound, [CuCl₂(C₁₂H₈N₂)], the Cu^II atom adopts a distorted tetrahedral coordination formed by two N atoms from one 1,10-phenanthroline ligand and two Cl atoms. In the crystal structure, molecules form intermolecular C—H...Cl contacts and π–π stacking interactions [centroid-to-centroid distances = 3.803 and 3.671 Å]. The shortest intermolecular Cu...Cl contacts are 4.306 (3) Å.

The Zn^II ion in the title complex, [Zn(C₉H₄NO₄S)(C₃H₄N₂)₂], is coordinated by an N atom and an O atom of a deprotonated tridentate Schiff base ligand, and two N atoms from two different imidazole ligands in a distorted tetrahedral geometry. In the crystal structure, molecules are connected via intermolecular N—H...O hydrogen bonds, forming extended one-dimensional chains along [111].

The Sn atom in the title compound, [Sn(C₆H₅)₃(C₁₀H₆NO₂)(CH₄O)], adopts a distorted SnO₂C₃ trigonal–bipyramidal geometry. The O atom of the carboxylate group occupies one of the axial sites and the O atom of the methanol molecule occupies the other. In the crystal structure, a bifurcated O—H...(O,N) hydrogen bond links adjacent molecules.

In the title complex, [Cd(C₄O₄)(C₁₀H₈N₂)]_n, the Cd atom exists in a trigonal-prismatic geometry that is defined by the two N atoms of a 1,10-phenanthroline ligand and the four carboxylate O atoms of two different acetylenedicarboxylate dianions. Adjacent Cd atoms are bridged by acetylenedicarboxylate dianions, giving rise to a two-dimensional structure parallel to (100).

The title complex, [Ni(SO₄)(C₁₉H₁₇N₇)]·2H₂O or [Ni(SO₄)(dpdapt)]·2H₂O [dpdapt is 6-phenyl-2,4-bis(2-pyridylamino)-1,3,5-triazine], has a distorted trigonal–bipyramidal coordination where the equatorial plane contains the N atoms of the pyridine rings and one of the O atoms of the sulfate group, while the axial positions are occupied by the other O atom and the N atom of the triazine ring of the dpdapt ligand. The complex lies across a mirror plane. The H atoms of the NH group of the dpdapt ligand and of the solvent water molecule are involved in hydrogen bonds, which form an infinite two-dimensional corrugated sheet parallel to the ac plane. The water molecule is disordered over two positions; the site occupancy factors are 0.58 and 0.42.

The racemic title compound, K₂[Co₂(C₁₀H₁₃NO₆)₂(OH)₂]·4H₂O, exhibits a slightly distorted octahedral coordination of the Co atoms, possibly because of constraints imposed by the tetradentate ligand. The ten-coordinate potassium cation provides a link between the ligating anions of the dinuclear dianion via the carbonyl O atoms of the N,N-bis(carboxylatomethyl)leucinate ligands, forming a polymeric three-dimensional network. The complex crystallizes in the orthorombic space group, Cmca, resulting in Co dimers situated around special positions in the unit cell, which leads to a 50% disorder of the bridging hydroxido H atoms and the isopropyl substituents.

The Ag^I atom in the title complex, [Ag(C₇H₄NO₃S)(C₅H₆N₂)], adopts an almost linear AgN₂ geometry with a saccharinate anion and a 3-aminopyridine ligand. Discrete molecules are linked by N—H...O hydrogen bonds into a three-dimensional network.

In the title complex, [CuCl₂(C₁₁H₂₁N₃O)], the five-coordinate Cu atom has a distorted square-pyramidal configuration. The crystal packing is stabilized by intermolecular N—H...Cl hydrogen-bonding interactions. The furan ring is disordered over two position, with site occupancy factors of ca. 0.6 and 0.4.

In the mononuclear title complex, [Ni(C₇H₂N₂O₇)(C₄H₈N₂O₂)(H₂O)], the nickel(II) ion is five-coordinated in a distorted square-pyramidal geometry by two N atoms from a dimethylglyoxime molecule, two O atoms from a 2-oxido-3,5-dinitrobenzoate anion and one O atom from a water molecule. Strong hydrogen bonds connect discrete adjacent molecules, forming a ribbon parallel to the b axis.

In the title compound, (C₁₂H₁₀Br₂N)₂[Ni(C₄N₂S₂)₂], the Ni^II atom of the anion lies on an inversion centre and exhibits a square-planar coordination geometry. The benzene and pyridine rings of the cation make a dihedral angle of 74.6 (3)°. The cations (C1 and C2) and anions (A) are arranged in a …C1C2AC1C2AC1C2… pattern along the [10] direction and are linked by C—H...S hydrogen bonds and π–π stacking interactions involving the benzene ring [centroid–centroid separation = 3.778 (3) Å].

In the title complex, [Zn(C₁₄H₁₃N₃O₂)₂(H₂O)₄](NO₃)₂, the Zn atom is located on a center of symmetry. The Zn—O bond distances are 2.0816 (19) and 2.1356 (18) Å, and the Zn—N bond distance is 2.166 (2) Å. The coordination polyhedron is a slightly distorted octahedron. The crystal structure is stabilized by O—H(coordinated water)...O(NO₃⁻ or carbonyl O) and N—H(imine)...O(NO₃⁻) hydrogen bonds, forming a three-dimensional network.

In the title compound, {[Na₂(C₁₂H₈N₂)₂(H₂O)₅]Br₂·C₁₂H₈N₂}_n, the Na^I ions in polymeric chains adopt two different types of coordination geometry. In one type, the Na^I ion is coordinated by two N atoms from 1,10-phenanthroline (L) and four water molecules in a distorted octahedral geometry, while in the other type, the Na^I ion is coordinated by two N atoms from L and three water molecules in a distorted trigonal–bipyramidal geometry. The coordinating bond lengths Na—N [2.425 (5)–2.517 (5) Å] and Na—O [2.353 (5)–2.574 (4) Å] are normal. The crystal packing exhibits an extensive hydrogen-bonding network (O—H...N, O—H...O and O—H...Br) and π–π interactions (centroid–centroid distances are 3.821 and 3.896 Å).

In the title complex, [CuFe(C₅H₅)(C₂₀H₁₄N₃)(C₁₀H₈N₂)](BF₄)₂, the Cu^II atom is five-coordinated by a tridentate chelating 4′-ferrocenyl-2,2′:6′,2"-terpyridine (fctpy) ligand and a bidentate chelating 2,2′-bipyridine (bpy) ligand. The coordination polyhedron is distorted square-pyramidal with an N atom from the bipyridine ligand in the apical position at a Cu—N distance of 2.195 (3) Å. In the crystal structure, tetrafluoridoborate counter-ions are involved as acceptors in intermolecular C—H...F hydrogen-bonding interactions with both the bipyridyl and terpyridyl ligands, resulting in a three-dimensional supramolecular structure.

In the centrosymmetric dinuclear molecule of the title compound, [Zn₂(C₈H₇O₃)₂Cl₂(H₂O)₂], the Zn ions are bridged by two phenolate O atoms, with a Zn...Zn distance of 3.1216 (6) Å, forming a Zn₂O₂ four-membered ring. Each Zn coordination is completed by a further bidentate 4-hydroxy-3-methoxybenzaldehyde ion, one chloride ion and one water molecule. The water molecules are involved in hydrogen bonds, which stabilize the crystal structure.

In the symmetric unit of the title compound, [Co(C₇H₅O₃)(C₁₄H₁₂N₂)(H₂O)₂]NO₃, the Co²⁺ cation is coordinated by a bidentate 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand, a bidentate 3-hydroxybenzoate anion and two water molecules in a distorted octahedral environment. The 3-hydroxybenzoate ligand, Co atom and nitrate anion are situated on a crystallographic twofold rotation axis. The OH group of the benzoate anion is disordered over two symmetry-related positions with site-occupancy factors of 0.5. An extensive series of O—H...O hydrogen bonds, involving water molecules and 3-hydroxybenzoate and nitrate anions, and weak C—H...O hydrogen bonds lead to a supramolecular network structure.

The complete title trinuclear Cu^II complex, [Cu₃Cl₆(C₁₄H₁₆N₃O₂)₂], is generated by twofold symmetry with one Cu atom lying on the rotation axis. The central Cu atom adopts a distorted tetrahedral CuCl₄ geometry. The terminal Cu atom is five-coordinated in a distorted square-pyramidal coordination environment consisting of three N atoms of the ligand, one bridging Cl atom and one terminal Cl atom. Intermolecular C—H...Cl hydrogen bonds help to establish the packing.

The title compound, [Cr₂(C₁₆H₁₈P₂)(CO)₁₀]·CDCl₃, crystallizes with one CDCl₃ solvent molecule per formula unit, with the solvent molecule residing in a niche between the two phenyl rings. The crystal studied was an inversion twin. The crystal packing shows secondary C—H...O interactions.

The title compound, [Sn(CH₃)₂(C₆H₅O₂S)Cl]_n, forms an extended one-dimensional chain structure which propagates along the a-axis direction. The two independent SnO₂C₂Cl centres have distorted trigonal–bipyramidal environments with the coordinated O atoms in the axial positions. Both thiophene groups are disordered over two sites, with approximate occupancies of 0.5:0.5 and 0.78:0.22.

The title compound, {[Ag(C₁₅H₁₆S₂)₂]SbF₆·0.5C₄H₁₀O}_n, was obtained from the self-assembly of AgSbF₆ and 1,3-bis(phenylsulfanyl)propane. Each Ag^I ion is coordinated by four S atoms from different ligands, forming a distorted tethrahedral geometry. Each ligand links adjacent Ag^I ions, forming an extended two-dimensional grid-like framework. SbF₆⁻ ions, which are incorporated into the cavities of the network, complete and stabilize the structure. One of the phenyl rings is disordered over two sites, the ratio of occupancies being 0.508 (4):0.492 (4).

In the title compound, [Rh(C₉H₇ClNO)(C₁₈H₁₂Cl₃P)(CO)], the phosphine ligand is trans to the N atom of the quinolinolate ligand. This indicates that changes in the electronic properties of the quinolinolate backbone have a negligible influence on the phosphine substitution. Important geometrical parameters are the quinolinolate bite angle of 80.15 (9)° and the Rh—P bond distance of 2.2478 (9) Å, the effective cone angle (Θ_E) for the phosphine ligand being 165°. Quinoline ligand-to-ligand π-stacking is in a tail-to-tail fashion with an intermolecular distance of 3.26 Å. The molecule also exhibits intramolecular C—H...Cl and C—H...O hydrogen bonds.

The title compound, [Mn(C₂H₂N₉)₂(H₂O)₂]·2H₂O, has been prepared under hydrothermal conditions. The Mn^II atom, lying on an inversion center, is coordinated in an octahedral geometry defined by four N atoms from two di-1H-tetrazol-5-ylaminate ligands in the equatorial plane and two water molecules in the axial positions. The complex molecules are linked into a three-dimensional network through O—H...N, N—H...O and N—H...N hydrogen bonds.

The central Re atom of the mononuclear title complex, [Re(C₈H₁₈NS₂)(C₆H₄OS)O], is five-coordinate (ReNOS₃) with a square-pyramidal geometry comprising a tridentate 2,2′-(propylimino)diethanethiolate ligand, a 4-methoxybenzenethiolate ligand and a doubly-bonded O atom.

Carboxylate bridging in the title neodymium(III) coordination polymer, {[Nd₂(C₄H₄O₄)₃(H₂O)₂]·H₂O}_n, leads to a three-dimensional network architecture. One of the two independent succinate groups lies on a centre of inversion whereas the other lies on a general position; both engage in μ₄-bridging. The motif is consolidated by hydrogen bonds that involve the coordinated water molecule. The uncoordinated water molecule, which lies on a twofold rotation axis, is only weakly hydrogen bonded to the network. The Nd^III atom shows tricapped trigonal prismatic coordination.

The title compound, [Fe(C₅H₅)(C₂₂H₂₇O₃)], which forms an extended conjugated system and appears in the enol form, is mainly stabilized by an intramolecular hydrogen bond. The Fe—C bond distances are nearly equal with a mean value of 2.0312 Å. The two cyclopentadienyl rings are almost parallel to each other, as shown by the dihedral angle of 0.97 (17)°. In the structure, ferrocenyl is the more powerful electron-donating group, with the result that the carbonyl group substituted on the benzene ring has the enol form.

In the Cu^II title complex, [Cu(C₂₁H₂₁N₇O₆)]·1.5CH₄O, two independent half-molecules of the title complex and one and a half methanol solvent molecules are in the asymmetric unit. The title complex possesses crystallographic C₂ symmetry. One methanol molecule is disordered around a twofold axis. The title complex geometry agrees well with that of the dihydrate determined earlier with the exception of an N—Cu—N angle deviating by almost 10°. The Cu^II centre is in a distorted square-pyramidal geometry, and intermolecular hydrogen bonds stabilize the molecular packing.

In the title complex, [Zn(C₉H₇O₃)(C₂₇H₂₇N₇)]ClO₄·C₃H₇NO·C₂H₆O·0.5CH₄O, the Zn^II ion is five-coordinated by four N atoms from a tris(N-methylbenzimidazol-2-ylmethyl)amine ligand and one O atom from a 4-hydroxycinnamate ligand in a distorted trigonal–bipyramidal geometry. The atoms of the ethanol and methanol solvent molecules are disordered over two sites with equal occupancy.

In the title compound, [Cd(C₁₁H₉ClN₃O₂)₂]·4H₂O, the Cd^II atom is coordinated by four N atoms and two O atoms from two picolinate ligands in a distorted octahedral geometry. In the crystal structure, molecules are linked together by intermolecular O—H...O hydrogen bonds.

In the title compound, [Co(C₁₁H₉ClN₃O₂)₂]·2.5H₂O, the Co^II atom, which lies on a twofold rotation axis, is coordinated by four N atoms and two O atoms from two ligands in a distorted octahedral geometry. In the crystal structure, molecules are linked together by intermolecular O—H...O hydrogen bonds.

The title complex, [MnCl₂(C₂₁H₁₉N₃)]·0.5CH₂Cl₂ or [MnCl₂(Plep)]·0.5CH₂Cl₂ {Plep is 2,6-bis[1-(phenylimino)ethyl]pyridine, derived from the condensation of 2,6-diacetylpyridine and aniline in methanol} is composed of two crystallographically independent [MnCl₂(Plep)] neutral units and a CH₂Cl₂ solvent molecule. Both complex molecules have similar geometries in which the Mn^II atom is coordinated by the N atoms of pyridine and the two imine groups of a neutral Schiff base, and by two chloride anions in a distorted trigonal–bipyramidal geometry. The structure of each [MnCl₂(Plep)] unit exhibits a pseudo-mirror plane through the metal atom, two chloride anions and the pyridine ring. The crystal packing is stabilized by intermolecular C—H...Cl and C—H...π and interactions.

In the title compound, {[Ag(C₁₀H₈NO₃S)(C₁₈H₁₅P)₂]·H₂O}_n, each Ag^I cation is four coordinated by two P atoms from two different triphenylphosphine ligands, and by one N atom and one sulfonate O atom from different 6-aminonaphthalene-1-sulfonate anions in a distorted tetrahedral geometry. Each 6-aminonaphthalene-1-sulfonate ligand bridges two Ag^I centers, resulting in the formation of polymeric chains parallel to the a axis. Intermolecular O—H...O and N—H...O hydrogen bonds contribute to the crystal packing stability. One phenyl ring is disordered over two positions; the site occupancies are 0.68 and 0.32.

The present study of the title compound, [Co(C₃H₈N₂O₂)₃](NO₃)₂, probably represents a correction to that reported by Zhang, Song, Zhang, Ma & Yu [Z. Naturforsch. Teil B (2005), 60, 505–510] with a doubled a axis. As modelled here, there are four independent cations, each built up around a fac-CoN₃O₃ octahedron, and eight anions in the asymmetric unit. Two of the cations show disorder in one of their ethyl side chains in ratios of 0.712 (10):0.288 (10) and 0.612 (7):0.388 (8). Numerous cation-to-anion N—H...O hydrogen bonds, many of which are bifurcated, help to establish the crystal packing.

The asymmetric unit of the title complex, aqua[1-cyclopropyl-7-(4-ethylpiperazin-1-yl)-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylato](1,10-phenanthroline)copper(II) nitrate dihydrate, [Cu(C₁₉H₂₁FN₃O₃)(C₁₂H₈N₂)(H₂O)]NO₃·2H₂O, contains one [Cu(erx)(phen)(H₂O)]⁺ cation, one NO₃⁻ anion and two solvent water molecules (erx is enrofloxacin and phen is 1,10-phenanthroline). The Cu^II ion adopts a slightly distorted square-pyramidal geometry, coordinated by two O atoms of the erx ligand and two N atoms of the phen ligand in the basal plane, and by a water molecule in the apical position. The Cu^II ion deviates from the basal plane by 0.1439 (7) Å. The piperazine ring belonging to erx has a slightly twisted chair conformation. Coordinated and uncoordinated water molecules participate in a hydrogen-bonding network including both cations and anions, to produce a three-dimensional supramolecular structure.

In the title compound, [Cr₂(C₁₆H₁₂Br₂N₂O₂)₂O], Cr^III is chelated by a Schiff base ligand through two N and two O atoms, and is pentacoordinate, with a bridging oxide ion. The coordination geometry can be described as square-based pyramidal, with the bridging oxide in the apical site, giving the shortest bond. The bridging ligand lies on a crystallographic twofold rotation axis.

The Ni atom in the title compound, [Ni(C₁₉H₁₄ClN₄O)₂]·2C₂H₆OS, which lies on a centre of inversion, is N,O-chelated by the two monoanionic ligands in a square-planar geometry. The asymmetric unit also contains a dimethyl sulfoxide solvent molecule. The donor amino sites of the metal-bearing molecule interact with the solvent molecules to furnish a hydrogen-bonded layer structure.

The Co^II ion in the title complex, [Co(NCS)₂(C₆H₇NO)₂], lies on a crystallographic twofold axis and is in a slightly distorted octahedral coordination environment. In the crystal structure, intermolecular O—H...S hydrogen bonds link molecules to form a two-dimensional network perpendicular to the c axis.

In the title compound, [Ag(C₁₀H₈NO₃S)(C₈H₁₂N₂)]_n, the Ag⁺ cation is three-coordinated by two N atoms from two 2,3,5,6-tetramethylpyrazine ligands and one O atom from a 7-aminonaphthalene-1-sulfonate anion. The 2,3,5,6-tetramethylpyrazine ligand acts as a bridging bidentate ligand, linking the Ag^I centres into a one-dimensional chain. The chains are interconnected via intermolecular N—H...O hydrogen bonds and C—H...π interactions, resulting in the formation of a three-dimensional framework.

In the title compound, [MnCl₂(C₁₀H₁₁N₃)₂]·2CH₃OH, both naphthyridine ligands coordinate to the Mn^II ion via two N atoms in a bidentate chelating mode. The Mn^II centre is furthermore coordinated by two Cl ligands to form an octahedral geometry. In addition, there are two methanol molecules in the asymmetric unit. The crystal packing is stabilized by O—H...Cl, N—H...O and N—H...Cl hydrogen bonds.

In the title compound, [Co(C₁₇H₁₀Br₂NO)₂(C₃H₇NO)₂], the cobalt(II) cation is coordinated by two N and two O atoms from two different Schiff base ligands, and two O atoms from dimethylformamide molecules, forming a slightly distorted octahedral geometry. In the crystal structure, C—H...Br hydrogen bonds link the molecules in rows.

In the title centrosymmetric compound, [Cd(C₈H₇N₃)₂(H₂O)₂](NO₃)₂, the Cd^II atom lies on a center of symmetry and is six-coordinated by four N donors from two distinct chelating 3-(2-pyridyl)-1H-pyrazole ligands and two O atoms from two water molecules, in a distorted octahedral geometry. The Cd^II mononuclear units and nitrate ions are linked through intermolecular O—H...O, N—H...O and C—H...O hydrogen-bonding interactions, forming a three-dimensional framework.

The title compound, [Cu(C₁₀H₁₂N₃O₃)(NCS)], is a thiocyanate-bridged polynuclear copper(II) complex. The Cu^II atom is pentacoordinated by two N atoms and one O atom of the Schiff base ligand, 4-nitro-2-[(2-methylaminoethylimino)methyl]phenol (HNP), and by two N atoms from symmetry-related thiocyanate anions, forming a slightly distorted square-pyramidal coordination configuration. The Cu(NP) units are linked through the bridging thiocyanate anions, forming chains running along the c direction.

The title compound, [Cu₂(C₁₀H₁₁BrClN₂O)₂(NCS)₂], is a centrosymmetric dithiocyanate-bridged binuclear copper(II) complex. The Cu^II atoms are pentacoordinated by the N,N′,O-donor atoms of the Schiff base ligand 2-bromo-4-chloro-6-[(2-methylaminoethylimino)methyl]phenol (HBCP), and by one N and one S atom from two symmetry-related thiocyanate anions, so forming a slightly distorted square-pyramidal coordination configuration. The Cu...Cu distance is 5.480 (2) Å.

In the centrosymmetric binuclear title complex, [Pb₂(C₇H₅O₃)₄(C₁₄H₁₂N₂)₂], each Pb^II ion is coordinated by two N atoms from a 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand and four O atoms from three 4-hydroxybenzoate anions in a distorted octahedral environment. The 4-hydroxybenzoate groups coordinate to each Pb^II atom in two different ways. Two 4-hydroxybenzoate ions behave as chelating ligands to a single Pb atom, and the other two form bridges between the two Pb atoms, forming a centrosymmetric eight-membered ring in the binuclear structure. Molecules are linked into a two-dimensional framework by O—H...O hydrogen bonds. The packing is further stabilized by π–π interactions between the dmphen rings of neighboring molecules, with a distance of 3.327 Å between the planes of the dmphen ligands.

In the title mononuclear complex, [Ag(C₁₂H₈N₄O)₂]NO₃·H₂O, the Ag^I ion is coordinated linearly by two pyridyl N atoms from two crystallographically independent monodentate 2,5-di-4-pyridyl-1,3,4-oxadiazole (4-bpo) ligands. In addition, the asymmetric unit contains one nitrate anion and one solvent water molecule. In the crystal structure, nitrate anions connect to Ag^I ions via weak Ag...O interactions [Ag...O = 2.836 (3) Å] and to two symmetry-related solvent water molecules via O—H...O hydrogen bonds, to afford a one-dimensional herring-bone-like motif along [100]. Significant π–π stacking interactions [Cg...Cg = 3.614 (2)–3.721 (2) Å, where Cg is the centroid of a pyridyl or oxadiazole ring] are also found between two adjacent one-dimensional motifs, resulting in a double-strand supramolecular array.

The structure of the title complex, [Zn(NCS)₂(C₈H₁₂N₆)]_n, exhibits a one-dimensional zigzag chain through a 1,4-bis(1,2,4-triazol-1-yl)butane bridge, in which the Zn^II atom, lying on a twofold rotation axis, is in a distorted tetrahedral environment formed by two N atoms of the triazoles and two N atoms from two thiocyanate ligands.

In the title complex, [Co(C₁₆H₁₀O₄)(C₁₂H₈N₂)(H₂O)₂]_n, the Co^II ion exists in an octahedral geometry, coordinated by two N atoms of a 1,10-phenanthroline ligand, two carboxylate O atoms of two different trans-stilbene-4,4′-dicarboxylate ligands and two water molecules. The trans-stilbene-4,4′-dicarboxylate bridges give rise to a linear chain structure. These chains are further interconnected through intermolecular hydrogen bonds and π–π stacking interactions between one of the rings of the 1,10-phenanthroline ligand and a symmetry-related ring [centroid-to-centroid distance 3.6153 (8) Å], to form a three-dimensional supramolecular network.

In the title compound, [Cu(C₁₃H₆F₄O₂)₂(C₁₂H₈N₂)(H₂O)]·C₆H₂F₄, each Cu^II ion is coordinated by two N atoms [Cu—N = 1.985 (6) and 2.052 (6) Å] from a 1,10-phenanthroline ligand, and three O atoms [Cu—O = 1.922 (6)–2.243 (5) Å] from two 2,3,4,5-tetrafluorobenzoate ligands and a water molecule, respectively, in a distorted square-pyramidal geometry. Intermolecular O—H...O hydrogen bonds link the complex molecules into chains parallel to the a axis. The crystal packing exhibits weak C—H...O hydrogen bonds and π–π interactions, as evidenced by a short distance of 3.717 (13) Å between the centroids of the benzene rings of neighbouring solvent molecules. One F atom is disordered over two positions; the site occupancy factors are 0.57 and 0.43.

In the tetranuclear title compound, [Al₄(C₃H₇O)₁₂], one Al atom is six-coordinate, with an octahedral coordination geometry, whereas the other three are four-coordinate with tetrahedral geometries. Two of the three symmetry-independent Al atoms lie on special positions of site symmetry 2.

In the title compound, catena-poly[[dibenzyldichloridotin(IV)]-μ-1,4-bis(pyridin-3-ylmethoxy)benzene], [SnCl₂(C₇H₇)₂(C₁₈H₁₆N₂O₂)]_n, the dibenzyldichlorostannane molecules are linked by the neutral 1,4-bis(pyridin-3-ylmethoxy)benzene ligands to generate an infinite coordination polymer. Both the Sn atom and the linking ligand reside on centers of inversion. The Sn atom displays a distorted octahedral geometry that consists of two benzyl groups, two chloride ions and two N atoms from different 1,4-bis(pyridin-3-ylmethoxy)benzene ligands.

The title Pb^II coordination polymer, {[Pb(C₂₄H₂₀N₆)₂](SCN)₂}_n, was obtained by the reaction of Pb(CH₃COO)₂·3H₂O, KSCN and 1,2-bis{[2-(2-pyridyl)-1H-imidazol-1-yl]methyl}benzene (hereafter L). Each L molecule coordinates to two Pb^II cations through the four aromatic N atoms, thus acting as a bridging bis-bidentate ligand. The Pb^II cations, which lie on inversion centres, are bridged by four L molecules, forming a two-dimensional (4,4)-sheet. The SCN⁻ anions act as counter-ions and are uncoordinated.

All interatomic distances and angles in the title compound, [RuCl₂(C₅H₅N)₃(C₁₈H₁₅P)], are normal. The Ru atom is octahedrally and the P atom tetrahedrally coordinated. The structure is stabilized by several weak C—H...Cl intramolecular hydrogen bonds.

In the polymeric title complex, [Ni(C₂H₃O₂)₂(C₁₂H₈N₂)]_n, Ni^II ions are bridged by single syn–anti acetate ligands. Each Ni atom is five-coordinated by two 1,10-phenanthroline N atoms and three O atoms of acetate ligands in a distorted square-pyramidal coordination geometry. In the crystal structure, C—H...O hydrogen bonds result in the formation of a polymeric ribbon structure.

The asymmetric unit of the title compound, [Co(H₂O)₆](C₆H₆NO₃S)₂, contains one half-cation and one anion; the Co atom lies on an inversion centre. In the crystal structure, intermolecular O—H...O and O—H...S hydrogen bonds result in the formation of a supramolecular network. The conformation of the anion is stabilized by an intramolecular C—H...O hydrogen-bonding interaction.

In the title compound, [Mn(C₂₀H₁₆N₄O₂)Cl(H₂O)]·C₃H₇NO, or [Mn(bmpb)Cl(H₂O)]·DMF [H₂bmpb = 1,2-bis(4′-methylpyridine-2′-carboxamido)benzene and DMF is dimethylformamide], the Mn^III ion is six-coordinate in the form of a distorted octahedron with two pyridine and two deprotonated amide N atoms in the equatorial plane, while the two axial sites are occupied by a chloride ion and an O atom. The structure displays O—H...O hydrogen bonds.

The polymeric structure of the title compound, poly[[diaquabis(μ-biphenyl-4,4′-disulfonato)tetrapotassium(I)] dihydrate], {[K₂(C₁₂H₈O₆S₂)(H₂O)]·H₂O}_n, is based on an asymmetric unit comprising three independent and different potassium centres, one six-coordinate [K—O = 2.657 (3)–2.866 (5) Å], one seven-coordinate [K—O = 2.703 (3)–3.040 (4) Å], and the third ten-coordinate [K—O = 2.751 (3)–3.079 (4) Å], with two of these lying on crystallographic mirror planes. The four half-occupancy water molecules also lie on the mirror planes with two coordinated (one monodentate, the other bidentate bridging) and two as molecules of solvation. The interlinked coordination polyhedra form chains which are joined laterally through the biphenyl residues as well as through head-to-tail water hydrogen-bonding interactions, giving a two-dimensional structure.

The crystal structure, electronic spectroscopy and ¹H NMR data for the title compound, [Zn(C₅₂H₄₄N₄O₈)]·4CH₂Cl₂, are reported. The asymmetric unit consists of 0.5 zinc–porphyrin and two molecules of dichloromethane. The zinc ion is at a crystallographic inversion center and is four-coordinate with a planar porphyrin ligand.

The Sn atom in the title compound, [Sn(CH₃)₂(C₁₀H₆NO₂)Cl], has a distorted SnC₂NOCl trigonal–bipyramidal geometry with the quinoline N atom and Cl atom occupying the axial sites.

In the title compound, [Cu(C₁₆H₁₆N₄)₂](ClO₄)₂, the Cu^II atom lies on an inversion centre and has a distorted square-planar geometry. In each ligand, the dihedral angle between the triazole and pyridine rings is 9.1 (3)°, and that between the triazole and benzene rings is 85.01 (14)°.

In the monocationic octahedral complex, [RuCl(C₆H₁₈N₄)(CO)]Cl, the ruthenium(II) centre is coordinated by a chloride and a carbonyl ligand and by the tetradentate tris(2-aminoethyl)amine (tren) chelator. The complex has approximate non-crystallographic C_s symmetry. In the crystal structure, N—H...Cl hydrogen bonds are found, mainly with the chloride counter-ion as the acceptor.

In the structure of the title compound, [Ni₂(N₃)₄(C₅H₅N)₄]_n, neutral chains of Ni^II atoms are bridged alternately by double end-on and double end-to-end azide bridges. Each Ni^II center is located on a crystallographic general position and in a slightly distorted octahedral coordination environment with two pyridine ligands in the trans positions. Both end-on and end-to-end double azide bridges become equivalent because of the inversion centers lying between each pair of adjacent Ni^II atoms. In the chain, the Ni...Ni separations across the end-on and end-to-end azide bridges are 3.236 (4) and 4.975 (4) Å, respectively, and the end-on azide bridging Ni—N—Ni angle is 100.8 (2)°.

The title complex, [Ni(C₂H₁N₉)(C₁₀H₈N₂)₂]·6H₂O, was prepared under hydrothermal reaction conditions. The asymmetric unit contains the nickel complex and six solvent water molecules. The Ni^II ion is coordinated in a distorted octahedral geometry defined by four N atoms from two 2,2′-bipyridine ligands and two N atoms from the 5,5′-iminobis(tetrazolate) (BTA²⁻) anions. In the crystal structure, an extensive range of O—H...N and O—H...O hydrogen bonds links the complex and the water molecules into a three-dimensional network.

In the title compound, [ZnCl₂(C₆H₅NO)₂], the Zn^II atom lies on a mirror plane, and is coordinated by two N atoms from two pyridine-3-carbaldehyde ligands and two Cl ligands in a distorted tetrahedral geometry. The packing is governed by intermolecular C—H...O hydrogen-bonding interactions.

The asymmetric unit of the title complex, [Bi(C₁₀H₉N₂O₄)₂Cl]·5H₂O, contains the Bi^III complex and five solvent water molecules. The Bi atom is chelated by four O atoms and two N atoms of two (E)-2-{(Z)-[(4-hydroxyphenyl)oxidomethylene]hydrazono}propanoate ligands. A chloride anion completes the coordination environment, with the seven-coordinate Bi atom adopting a distorted capped octahedral geometry. The molecules are connected by extensive O—H...O hydrogen-bonding interactions involving the solvent water molecules into a two-dimensional supramolecular network. One water molecule is disordered over two sites with almost equal occupancy factors.

In the title compound, [Fe(C₅H₅)(C₁₂H₇Cl₂O)], the cyclopentadienyl rings are almost parallel and eclipsed as typically found for similar monosubstituted ferrocene derivatives. Weak C—H...O and C—H...Cl hydrogen bonds link molecules into two-dimensional layers parallel to the ac plane in the crystal structure.

In the title compound, [Zn(C₁₃H₁₂N₂O)₂(H₂O)₂](NO₃)₂, the Zn^II ion is located on an inversion center. Each Zn center is six-coordinated by two O atoms and two N atoms from two benzamide ligands, and two O atoms from two water molecules, in a distorted octahedral geometry with normal values of Zn—N [2.1977 (19) Å] and Zn—O [2.0853 (17) and 2.1081 (18) Å] coordinating bonds. Intermolecular N—H...O and O—H...O hydrogen bonds link cations and anions into layers parallel to the bc plane.

The title compound, [Cr(C₅H₈O₂)(C₁₅H₁₁N₃)(H₂O)](ClO₄)₂·2H₂O·C₆H₁₈N₃OP, adopts a distorted octahedral configuration about the Cr^III atom, mainly due to the rigidity of the terpyridyl ligand. The N—Cr—N bite angles are significantly distorted from 90° at 78.3 (1) and 78.6 (1)°. The Cr—N bond distances vary between 1.998 (1) and 2.068 (1) Å. The crystal packing is controlled by hydrogen bonding and π-stacking, with an interplanar separation of 3.263 (2) Å.

The title complex, [Ag(C₇H₄NO₃S)(C₁₀H₈N₂)], has a mononuclear structure in which the Ag^I ion is coordinated by two N atoms from 2,2′-bipyridine and one N atom from saccharinate, forming a distorted T-shaped (or trigonal-planar) AgN₃ arrangement. The bite angle of bpy is 71.69 (6)°, which contributes significantly to the distortion of the coordination geometry. Molecules are connected by C—H...O and π(bpy)–π(bpy) interactions with a centroid–centroid separation of 3.6741 (13) Å.

The structure of the title compound, [Cd₂(C₁₂H₂₇O₃SSi)₄(C₁₀H₈N₂)]·2C₇H₈, consists of discrete molecules, with the two halves of the complex molecule related to each other by inversion symmetry. Two (tri-tert-butoxysilanothiolato)cadmium units are bridged through the 4,4′-bipyridyl ligand. The geometry of the Cd^II atoms is intermediate between square-pyramidal and trigonal-bipyramidal. The solvent toluene molecules pack in the voids between the mid-point of the 4,4′-bipyridine and the tert-butyl groups of an adjacent complex. There is disorder in the 4,4′-bipyridine molecule, with site occupancies of 0.506 (7):0.494 (7).

In the title compound, [Co(C₁₆H₈O₈)(C₁₀H₈N₂)₂]_n, the Co^II atom exhibits a distorted octahedral geometry defined by four O atoms from three 4,4′-dicarboxybiphenyl-3,3′-dicarboxylate ligands and two N atoms from two 4,4′-bipyridine ligands. In the crystal structure, one-dimensional molecular chains are connected by O—H...N hydrogen bonds, forming a two-dimensional supramolecular network.

The octahedral molecule of the title compound, [PtBr₄(C₂H₆S)₂], lies on an inversion centre [Pt—Br = 2.4654 (4) and 2.4761 (4) Å; Pt—S = 2.3624 (9) Å]. A similar set of bond distances is predicted by density functional theory.

In the centrosymmetric title compound, [Ag₂(NCS)₂(C₂₁H₂₁P)₄]·2CH₃CN, the Ag atom is coordinated by two phosphine ligands and two bridging thiocyanate ligands in a distorted tetrahedral configuration. The Ag—P bond distances are 2.4615 (7) and 2.5091 (7) Å, while the Ag—N and the Ag—S bond distances are 2.364 (2) and 2.3269 (18) Å, respectively. The crystal structure exhibits C—H...S hydrogen bonds.

In the ionic title complex, [Nd{CO(NH₂)₂}₄(H₂O)₄]I₃, the neodymium is located on a twofold rotation axis and is coordinated by four urea and four water molecules in a distorted square-antiprismatic geometry.

The title complex, [Fe(C₁₇H₁₄N₃)₂], was prepared by the reaction of 1,1′-diacetylferrocenedihydrazone with 2-quinolinecarboxaldehyde. The title compound adopts a Z configuration, in which the two quinoline groups from the two side chains are perfectly planar and nearly parallel.

In the title compound, {[Co(C₁₂H₁₀N₂)(H₂O)₂](C₆H₆NO₃S)₂·6H₂O}_n, a cobalt coordination polymer, the repeat unit comprises a cobalt complex cation, two 4-aminobenzenesulfonate anions and six uncoordinated water molecules. In the doubly charged cobalt cation, each Co atom lies on a center of symmetry and is six-coordinated in a distorted octahedral geometry formed by four O atoms of four coordinated water molecules, and two N atoms from two (E)-1,2-bis(4-pyridyl)ethylene (bpe) ligands. The bpe ligands bridge the Co atoms, forming a one-dimensional linear chain. Intermolecular O—H...O, O—H...N and N—H...O hydrogen-bonding interactions stabilize this chain structure.

In the title compound, [NiCl₂(C₁₀H₁₁N₃)₂]·CH₄O, the Ni^II ion lies on a crystallographic twofold axis and is coordinated in a distorted octahedral geometry by four N atoms from two bidentate naphthyridine ligands and two chlorine atoms. The unique methanol solvent molecule has half occupancy. In the crystal structure, intermolecular N—H...Cl and O—H...Cl hydrogen bonds connect molecules into one-dimensional chains which propagate along the c-axis direction.

The title compound, [PdCl₂(C₂₅H₄₆P₂)]·CH₂Cl₂, exhibits a distorted square-planar coordination about the Pd^II atom. The major distortion, seen in the P—Pd—P angle, is the result of the small bite angle of the diphosphine ligand. There is also a slight tetrahedral distortion from planarity, as measured by the dihedral angle of 2.26 (3)° between the PdP₂ and PdCl₂ planes. The dichloromethane solvent molecule is disordered over two sites with approximate occupancies of 0.58 and 0.42.

A new ion-pair complex, (C₁₂H₁₁FN)₂[Ni(C₄N₂S₂)₂] or (FBzPy)₂[Ni(imnt)₂], where FBzPy is 1-(4-fluorobenzyl)pyridinium and imnt is 2,2-dicyanoethene-1,1-dithiolate, was obtained by the direct reaction of NiCl₂, K₂(imnt) and (FBzPy)⁺Br⁻ in H₂O. The asymmetric unit contains a [FBzPy]⁺ cation and one half of the Ni[imnt]₂²⁻ anion. The Ni^II ion lies on an inversion centre and adopts a square-planar configuration. In the [FBzPy]⁺ cation, the benzene and pyridinium rings make a dihedral angle of 77.2 (3)°. In the crystal structure, C—H...N hydrogen bonds and π–π interactions [3.450 (3) Å] between ethenyl groups of the Ni[imnt]₂²⁻ anion and the pyridinium ring of the cation generate a three-dimensional network.

The title compound, [Cr(C₁₃H₂₁)₂] or [η⁵-1,3-(Me₃C)₂C₅H₃]₂Cr, a substituted chromocene, crystallizes with two independent half-molecules in the asymmetric unit, the molecules having twofold rotation symmetry. The compound is isostructural with the iron and cobalt analogues and is a bent metallocene.

The title compound, [PdBr(C₂₆H₄₃N₄O₂P₂)], a so-called palladium pincer complex, is a very efficient catalyst for the Suzuki cross-coupling reaction. The Pd atom exhibits a distorted square-planar coordination, typical for Pd^II complexes.

The title compound, [Cu(C₄H₆O₅)(C₆H₂N₂O)(H₂O)], has a six-coordinate Cu^II atom in a Jahn–Teller-distorted octahedral environment, coordinated by a tridentate oxydiacetate dianion, a bidentate pyridine-2-carboxamide ligand and a water molecule. The oxydiacetate chelates the Cu^II atom in a facial configuration.

In the title compound, [RuCl₂(C₁₀H₈N₂)₂], the Ru atom is located on a crystallographic inversion center. The bipyridine (bpy) ligands are thus coordinated trans, leading to steric interactions between pairs of opposite ortho-H atoms. The result is a marked deviation from the expected planarity of some units; the two pyridine rings of an individual bpy ligand enclose a 23.8 (1)° angle. With the RuN₄ plane, the same pyridine rings enclose angles of 22.3 (1) and 21.0 (1)°. The octahedral environment of the Ru atom, however, is not markedly distorted, with the Ru—Cl axis enclosing a 87.32 (6)° angle with the RuN₄ plane. In the crystal structure, the most significant intermolecular interaction, besides the expected π stacking [3.424 (3) Å perpendicular distance of parallel-stacked rings, and 3.389 (3) Å closest ring–atom distance for an inclined contact], is a weak C—H...Cl hydrogen bond.

The reaction of strontium(II) nitrate with pyridine-2,6-dicarboxylic acid, (pydcH₂) and 4,4′-bipyridine (bipy) in a 1:2:4 molar ratio leads to the formation of the title compound, (C₁₀H₁₀N₂)[Sr(C₇H₃NO₄)₂(H₂O)₃]·3H₂O, or (bipyH₂)[Sr(pydc)₂(H₂O)₃]·3H₂O, in aqueous solution. This compound is composed of an anionic complex, [Sr(pydc)₂(H₂O)₃]²⁻, a protonated 4,4′-bipyridine as a counter-ion, (bipyH₂)²⁺ (site symmetry ), and three uncoordinated water molecules. The anion is a nine-coordinate complex, with a distorted tricapped trigonal–prismatic geometry around the Sr^II atom. The coordination environment consists of two tridentate pyridine-2,6-dicarboxylate, (pydc)²⁻, groups and three O atoms of the coordinated water molecules. In the crystal structure, intermolecular O—H...O, N—H...O and C—H...O hydrogen bonds, π–π stacking between two aromatic rings [with distances of 3.5723 (7)–3.7494 (7) Å] and C—O...π stacking [distance of 3.5228 (12) Å] connect the various components into a supramolecular structure.

In the title compound, [Cd(C₇H₅O₂)₂(C₅H₆N₂)₂], the Cd^II atom is hexacoordinated by four O atoms from two crystallographically independent benzoate anions, and two pyridine N atoms from two crystallographically independent 2-aminopyridine molecules in a distorted octahedral geometry. In the crystal structure, the metal complexes are connected by N—H...O hydrogen bonding between the carboxylate O atoms of the benzoate anions and the amino H atoms of the 2-aminopyridine ligands. The benzoate and the aminopyridine rings are stacked in the direction of the crystallographic a axis, indicating π–π stacking interactions are present [centroid-centroid distance = 3.6790 (15) Å].

The title compound, Na⁺·C₆H₅O₂S₂⁻, at 100 (2) K has orthorhombic (Cmca) symmetry. The compound has a network structure. It is of interest with respect to inclusion phenomena and structure–activity relationships. The Na atoms are chelated by two different benzenesulfonothioate anions via α-S and O atoms. Additional coordination by O atoms of two other benzenesulfonothioate anions results in coordination number 6 for each Na atom in the extended two-dimensional polymeric structure. The structure exhibits disorder of the anion in the two-dimensional arrangement. The phenyl group is disordered equally over two positions.

The title compound, [Cu₂Fe₃(C₅H₅)₃(C₂H₃O₂)(C₆H₄O₂)₃(C₃H₇NO)₂], contains a dinuclear copper(II) paddlewheel unit, where the metal ions are bridged by the O atoms of three ferrocenecarboxylate groups and one acetate group. The crystal packing is mainly determined by van der Waals interactions.

The title complex, [MnCl₂(C₃H₇NO)₂(H₂O)₂], was obtained upon dissolution of a dimethoxyethane adduct of MnCl₂ in N,N-dimethylformamide. In the crystal structure, each Mn^II ion is located on a crystallographic inversion center, coordinated by two Cl [Mn—Cl = 2.53423 (17) Å] and four O [Mn—O = 2.1847 (5) and 2.2199 (6) Å] atoms in a distorted octahedral geometry. The complexes are linked into chains by complementary pairs of O—H...Cl hydrogen bonds. Adjacent chains pack via weaker O—H...Cl interactions or by interdigitation of —NMe₂ groups. The H atoms of two symmetry-related methyl groups are disordered between two orientations in a 0.51:0.49 ratio.

In the centrosymmetric title compound, [Mn₂(C₄H₂O₄)(NO₃)₂(C₁₄H₁₂N₂)₂(H₂O)₂], each Mn atom is six-coordinate in a distorted octahedral geometry. Molecules form stacks by π–π interactions (centroid–centroid distances of 3.826, 3.708 and 3.719 Å). The water molecules act as donors to form O—H...O hydrogen bonds. Moreover, the molecules are linked into chains along the a axis by C—H...O intermolecular hydrogen bonds.

The title compound, [Pt(CO₃)(C₁₈H₁₅P)₂]·0.5C₆H₆·0.5CH₂Cl₂, is isotructural with the analogous tetrahydrofuran [Gregg, Powell & Sawyer (1988). Acta Cryst. C44, 43–46] and benzene monosolvates [Scholz, Lerner & Bolte (2006). Acta Cryst. E62, m312–m313]. The Pt atom shows a distorted square-planar coordination.

In the title compound, [Co(C₈H₄O₄)(C₁₈H₁₀N₄)(H₂O)]_n, the Co^II atom is six-coordinated by three O atoms from two benzene-1,4-dicarboxylate (1,4-BDC) dianions (one bidentate and one monodentate), one water molecule and two N atoms from a bidentate dipyrido[3,2-a:2′,3′-c]phenazine ligand, resulting in a distorted cis-CoO₄N₂ octahedral geometry. The Co^II atoms are bridged by the 1,4-BDC ligands, forming a single-chain polymer structure. Both BDC ligands are centrosymmetric. Neighbouring chains interact through π–π interactions [minimum centroid–centroid separation = 3.459 (2) Å] and O—H...O hydrogen bonds.

The title compound, (C₈H₁₂N)₂[WS₄], was synthesized by the aqueous reaction of ammonium tetrasulfidotungstate(VI) with benzyl(methyl)amine in a 1:2 molar ratio. The compound is isotypic with the corresponding Mo analogue, (C₈H₁₂N)₂[MoS₄], and its structure consists of a slightly distorted tetrahedral [WS₄]²⁻ dianion and two crystallographically independent benzyl(methyl)ammonium cations, with all atoms located in general positions. The cations and anion are linked by weak N—H...S and C—H...S interactions, the strength and number of which can explain the observed W—S bond distances.

The title compound, [Mn₂(C₇H₃NO₄)₂(H₂O)₃]_n, has been synthesized under hydrothermal conditions. In the complex, the Mn atom is seven-coordinated by three symmetry-equivalent pyridine-2,6-dicarboxylate ligands and a water molecule in a pentagonal–bipyramidal coordination environment. A crystallographic twofold rotation axis passes through the bridging water molecule and between adjacent pairs of Mn atoms.

Zeise's dimer, [Pt₂Cl₄(C₂H₄)₂)], consists of two independent dimeric molecules in the unit cell, one of which is crystallographically centrosymmetric. All Pt atoms are essentially square planar with bridging and trans terminal chloride groups. The ethene groups are orthogonal to the molecular square plane. In the non-centrosymmetric molecule, the two square planes subtend an angle of 160.10 (13)° at the bridging Cl atoms. The crystal structure exhibits layers of molecules running approximately parallel to the (001) face, with a layer of the centrosymmetric dimer stacked directly between two layers of the non-centrosymmetric molecules [Pt...Pt = 4.053 (1) and 4.090 (1) Å]. Within this stack, the ethene groups of the central molecule are located betwen two terminal chloride groups of the adjacent molecules. Adjacent three-layer sandwiches are staggered from each other so that stacking occurs for only one square plane, disrupting any further interaction by one Pt atom but allowing a weaker Pt...Pt interaction [4.249 (1) Å]. The non-centrosymmetric molecule layer exhibits a weak hydrogen bond between a terminal chloride and an ethene H atom of an adjacent molecule.

In the title compound, [Zn₂(C₁₄H₈N₂O₄)(C₂H₈N₂)₂]·2C₃H₇NO·2H₂O, the Zn₂ complex molecule lies on a crystallographic inversion centre. The two Zn atoms are bridged by two diazine N atoms of a 1,2-bis(salicyloyl)hydrazine(4−) ligand (bsh⁴⁻); the inversion centre is located at the mid-point of the N—N bond. The coordination geometry of the Zn atom is distorted square-pyramidal. Each water molecule is linked with three surrounding binuclear complexes through four hydrogen bonds, resulting in a two-dimensional network.

In the monomeric hafnium(IV) title compound, [Hf(C₁₂H₂₁N₂Si)₂Cl₂], the Hf atom is N,N′-chelated by the N-silylated anilido ligand. The two ligands around the Hf atom are arranged cis to each other; a twofold rotation axis passes through the Hf atom. The two ends of the N—Si—N chelating unit exhibit different affinities to the metal center. The Zn—N_amino bond is longer than the Zn—N_anilido bond. Along with two Cl atoms, the six–coordinate Hf atom demonstrates a highly distorted octahedral geometry.

In the crystal structure of the title compound, [Cu(NO₃)(C₂H₄NO)(C₁₂H₈N₂)]_n, the Cu^II atoms are linked by acetamidate ligands, forming a chain. Each Cu^II atom is five-coordinated by two N atoms of the 1,10-phenanthroline ligand, one nitrate O atom, and one N and one O atoms of acetamidate in a trigonal-bipyramidal geometry. In the crystal structure, the chains are linked by hydrogen bonds into a polymeric ribbon structure.

In the binuclear cation of the title compound, [Ag₂(C₁₄H₁₄N₄)₂](C₆H₆NO₃S)₂·6H₂O, two Ag^I atoms are bridged by two 1,2-bis[(1H-imidazol-1-yl)methyl]benzene (IBI) ligands to form a 22-membered ring with crystallographic twofold rotation symmetry. Each Ag^I atom is two-coordinate, with a slightly distorted linear coordination geometry. The sulfonate anion does not coordinate to the silver ion but acts as a counteranion.

The title terbium coordination polymer, {[Tb₂(C₈H₄O₄)₃(H₂O)₂]}_n, was obtained by the hydrothermal reaction of Tb(NO₃)₃ with benzene-1,3-dicarboxylic acid (1,3-BDC) in alkaline aqueous solution. In the asymmetric unit, there are two crystallographically independent Tb^III ions: one seven-coordinate Tb centre is coordinated by six O atoms from six 1,3-BDC ligands and one water molecule, and the other Tb centre is eight-coordinate and surrounded by seven O atoms from six 1,3-BDC ligands and one water molecule. The bridging ligands link the metal centres, forming a three-dimensional network which is further stabilized by hydrogen-bonding interactions. One benzene ring is disordered over two positions with site occupancies of 0.60 (3) and 0.40 (3).

The Zr^IV atom in the title half-sandwich organometallic zirconium(IV) compound, [Zr(C₅H₅)(C₃₂H₃₅N₄Si)Cl₂]·CH₂Cl₂, is N,N′,N′′-chelated by the silyl-linked imino-amidinato monoanion in the first example of such an organozirconium derivative. The three N-donor atoms along with a Cl atom form a square, above and below which are the cyclopentadieny ring and the second Cl atom. The coordination geometry is octahedral.

The title zinc amide, [Zn(C₁₂H₂₁N₂Si)₂], which was synthesized by the metathetical reaction of [LiN(SiMe₂NMe₂)(2,6-Me₂C₆H₃)]₂ with zinc dichloride, has the Zn atom N,N′-chelated by the N-silylated anilide ligand in a square-planar environment. There are two independent molecules in the asymmetric unit; in both, the Zn—N_amine bonds are longer than the Zn—N_anilide bonds.

The zinc centre in the title complex, [Zn(C₈H₅O₃)₂(C₃H₄N₂)₂], shows tetrahedral coordination. Adjacent molecules are linked by N—H...O hydrogen bonds into a layer structure.

The asymmetric unit of the title compound, (C₁₄H₁₃N₂)₂[PtCl₆], contains one independent protonated 2,9-dimethyl-1,10-phenanthrolinium cation and half of a centrosymmetric [PtCl₆]²⁻ anion. The Pt ion has an octahedral coordination. Intramolecular N—H...Cl and N—H...N hydrogen bonds help to stabilize the structure.

In the title compound, [MnCl₂(C₁₆H₁₅N₅)(CH₄O)], the manganese(II) cation is six-coordinate, forming a distorted octahedral configuration with bis(1H-benzimidazol-2-ylmethyl)amine (IDB) serving as a neutral tridentate chelating ligand. Two imine and one amine N atoms from IDB and one Cl anion form the equatorial plane. The two axial positions are occupied by the methanol O atom and the other Cl anion. By a combination of two N–H...Cl and one O—H...Cl hydrogen bonds, molecules are linked into a three-dimensional network which is strengthened by weak C—H...π and π–π interactions [interplanar spacing = 3.343 (1) Å, ring-centroid separation = 3.728 (3) Å, corresponding to a ring offset of 1.650 (1) Å].

The title compound, {[Zn(C₈H₄O₅)(C₁₀H₈N₂)]·H₂O}_n, was synthesized by reacting Zn(NO₃)₂, 5-hydroxyisophthalic acid and 2,2′-bipyridine under hydrothermal conditions. Self-assembly between the bridging ligands, chelating ligands and metal ions results in a one-dimensional coordination polymer, in which the Zn^II atom is six-coordinate and shows a [ZnN₂O₄] octahedral geometry. The ribbons are interconnected by an extensive network of hydrogen bonds involving the water molecule, the hydroxyl group and the carboxylate O atoms, forming a two-dimensional layer. These layers are connected through π–π interactions between the pyridyl rings [centroid-to-centroid distance 3.57 (1) Å].

The title compound, [Cu(NO₃)₂(C₁₄H₁₃NO)₂], has been synthesized by the reaction of (E)-4-(4-methoxystyryl)pyridine with Cu(NO₃)₂ at room temperature in CH₃OH. The mononuclear complex sits across a crystallographic centre of inversion. The Cu^II ion is six-coordinated in a distorted octahedral fashion by the trans-disposed pyridine N atoms of two pyridine ligands and asymmetrically by two O atoms from each of the two nitrate ligands, where one of the Cu—O distances is quite long at 2.452 (3) Å.

The title complex, [Co(C₁₂H₈N₂)(H₂O)₄](C₁₀H₆O₆S₂)·2H₂O, was synthesized hydrothermally. The Co²⁺ cation, which lies on a twofold rotation axis, is six-coordinate. The anion is located on a centre of inversion. An extensive network of O—H...O hydrogen bonds links the components into a three-dimensional network.

In the asymmetric unit of the title compound, [Cd(C₂₀H₂₂N₂O₄)(H₂O)₂]·2.5H₂O, there are five water molecules and two independent mononuclear complex molecules in which the Cd^II ions are in distorted octahedral coordination environments, defined by N₂O₄ donor sets. In the crystal structure, extensive hydrogen bonding links molecules into one-dimensional chains along the b axis.

The title compound, [Cu(CN)(C₁₀H₉N₃)]_n, was prepared by the solvothermal treatment of CuCN with 2-[2-methyl(1H-benzo[d]imidazol-1-yl)]acetonitrile. The X-ray crystal structure shows that the title compound is a new cyano-bridged homometallic Cu^I coordination polymer in which the Cu^I atoms are linked by equally disordered CN groups, and are bonded to the N atom of the 2-[2-methyl(1H-benzo[d]imidazol-1-yl)]acetonitrile ligand. This ligand is alternately distributed along the zigzag chain. A three-dimensional structure is formed through a weak Cu—H interaction and π–π stacking between neighbouring benzimidazole ring systems.

The cation of the title salt, [Co₂(C₈H₅O₃)₂(C₁₀H₈N₂)₂(H₂O)₄](C₈H₅O₃)₂, or [Co₂(4-FBA)₂(2,2′-bipy)₂(H₂O)₄]·(4-FBA)₂ [where 4-FBA⁻ is the 4-formylbenzoate monoanion and 2,2′-bipy is 2,2′-bipyridine], is a dinuclear Co^II complex which is located on an inversion centre. The Co atom is six-coordinated by one O atom of a 4-FBA⁻ ligand, one 2,2′-bipy ligand and three water molecules in an octahedral geometry. The two Co atoms are bridged by two water molecules into a four-membered Co₂O₂ ring, with a Co...Co distance of 3.344 (4) Å. A linear chain running along the a axis is formed through hydrogen-bonding interactions between cations and anions. Two O atoms are disordered equally over two sites.

The Co^II atom in the title zwitterionic compound, [Co(C₅H₄NO₄S)₂(H₂O)₂]·6H₂O, is located on an inversion centre, and exists in an octahedral coordination geometry owing to chelation by the monoanion and coordination by water. A three-dimensional hydrogen-bonding framework is formed through O—H...O and N—H...O hydrogen-bonding interactions.

Two crystallographically independent cations of the title complex, [Cr(C₅H₇O₂)₂(H₂O)₂](ClO₄)·H₂O, are present in the asymmetric unit. Both cations are situated on centres of symmetry and share similar structural features. The geometry of the Cr³⁺ center is octahedral. The solvent water molecule and the perchlorate anion are involved in moderately strong hydrogen-bond interactions with the cations. In addition, neighboring cations are hydrogen-bonded together, resulting in a three-dimensional network.

The title complex is composed of two different structural units, [Co₂(C₁₄H₈N₂O₄)(C₅H₅N)₆]·[CoCl₃(C₅H₅N)]₂ or A·2B. The A unit is centrosymmetric. Each Co^II atom in A exhibits a distorted octahedral Co(ONO)(N)(N)(N) coordination environment, and the Co^II...Co^II distance is 4.409 (3) Å, whereas the cobalt(III) ion in B displays a distorted tetrahedral geometry. Group A is assembled into a two-dimensional network via intermolecular C—H...π interactions along the [101] direction.

In the title compound, (C₁₂H₉N₂)[SbBr₄(C₁₂H₈N₂)]·CH₂Cl₂, the Sb atom is six-coordinated by two N atoms of 1,10-phenanthroline and four Br atoms with a distorted cis-SbN₂Br₄ octahedral geometry. An uncoordinated phenanthrolinium cation interacts with the anion via an N—H...Br hydrogen bond.

In the title compound, [SbBr(C₄₅H₈NOS₂)₂], both organic ligands bond to Sb in an S,S′-bidentate mode, although one of the Sb—S bond lengths is much longer than the other three. A bromide ion completes the very distorted trigonal–bipyramidal geometry about the Sb atom.

The title compound, [Ir(C₁₁H₈N)₂(C₁₂H₁₂N₂)]PF₆, an iridium complex with two cyclometallated 2-phenylpyridine fragments and one 4,4′-dimethyl-2,2′-bipyridine unit, presents a distorted octahedral coordination geometry around the Ir atom. Charge balance is achieved through a hexafluoridophosphate anion. The coordination geometry of the two 2-phenylpyridine ligands around the Ir^III centre retains the cis-C—C and trans-N—N chelate dispositions.

The title compound, [Cu₂(CN)₃(C₁₀H₈N₂)]_n, crystallizes as a cyanido-bridged three-dimensional polymeric structure, where there coexist Cu^I and Cu^II ions along with μ₃- and μ₂-bridging cyanide groups. Each Cu^I ion is coordinated by four C atoms [Cu—C = 1.956 (3)–2.147 (3) Å] from two μ₃- and two μ₂-cyanide groups in a tetrahedral environment. The Cu^II ion is coordinated by two N atoms from the 2,2′-bipyridyl ligand and three N atoms from one μ₃- and two μ₂-cyanide groups in a square-pyramidal geometry [Cu—N = 1.967 (3)–2.183 (3) Å]. The Cu^I ions are paired by two C atoms from two cyanide groups into a dinuclear unit with a short Cu^I...Cu^I distance of 2.5398 (8) Å. Each dinuclear unit links six Cu^II ions by four μ₂- and two μ₃-cyanide groups to form a 4,6-connected framework, with Cu^I...Cu^II separations ranging from 4.864 (4) to 5.252 (4) Å.

In the title compound, [Cd(C₁₄H₈O₅)(C₂₄H₁₆N₂)]_n, the Cd^II atom is chelated by 4,7-diphenyl-1,10-phenanthroline (L) and is also bonded to four O atoms from three different 4,4′-oxydibenzoate (oba) ligands, resulting in a distorted cis-CdN₂O₄ octahedral geometry. The oba ligands bridge neighboring Cd^II atoms, generating a chain structure. Aromatic π–π stacking between L ligands in adjacent chains leads to a two-dimensional supramolecular layer [minimum centroid–centroid separation = 3.453 (6) Å].

In the title polymeric compound, {[Zn₂(C₈H₄O₄)₂(H₂O)₂]·2C₄H₉NO}_n, each of the terephthalate dianions uses both carboxylate ends to bridge a pair of water-coordinated Zn^II atoms [Zn...Zn = 2.9527 (4) Å] into a two-dimensional square-grid motif. One of the dianions lies on a special position of site symmetry , whereas the other lies on a general position. Each grid cavity contains two N,N-dimethylacetamide molecules.

The title compound, [Cu(C₁₂H₁₆N₃O₃)Cl]_n, is a chloride-bridged polymeric copper(II) complex. The Cu^II atom is five-coordinate in a square-pyramidal geometry, with one O and two N atoms of the Schiff base ligand and one Cl atom defining the basal plane [Cu...Cl = 2.2703 (8) Å] and a symmetry-related Cl atom occupying the apical position [2.8531 (9) Å]. The chloride-bridged polymeric chain runs along the b axis.

In the molecular structure of the title complex, [Sn(CH₃)₂(C₁₈H₁₂N₂O₃)]·CH₂Cl₂, the Sn atom is in a distorted trigonal–bipyramidal environment, with Sn—O distances of 2.083 (3) and 2.143 (2) Å. In the crystal structure, the molecules are stabilized by intermolecular O—H...N hydrogen bonds, giving rise to the formation of one-dimensional chains.

In the title compound, [Ni(C₈H₅N₄O₂)₂(H₂O)₄]·2H₂O, the Ni^II ion lies on an inversion centre and is coordinated by two N atoms from two 4-(tetrazol-1-yl)benzoate ligands and four O atoms from four water molecules in a slightly distorted octahedral geometry. In addition, there are two uncoordinated water molecules in the structure. The crystal structure is stabilized by intermolecular O—H...O hydrogen bonds.

The reaction of cadmium(II) nitrate tetrahydrate with the proton-transfer compound piperazinium pyridine-2,5-dicarboxylate, or (pipzH₂)(py-2,5-dc)·2H₂O (in which pipz is piperazine and py-2,5-dcH₂ is pyridine-2,5-dicarboxylic acid), in aqueous solution (molar ratio 1:2) leads to the formation of the title compound, (C₄H₁₂N₂)_1.5[Cd(C₇H₃NO₄)₂(C₇H₄NO₄)]·3H₂O or (pipzH₂)_1.5[Cd(py-2,5-dc)₂(py-2,5-dcH)]·3H₂O. The anion is a six-coordinate complex with a distorted octahedral geometry around Cd^II. Extensive intermolecular O—H...O, N—H...O and C—H...O hydrogen bonds involving the (py-2,5-dc)²⁻ ligand, (pipzH₂)²⁺ as counter-ion and the uncoordinated water molecules connect the various components into a supramolecular structure.

In the crystal structure of the title compound, [Eu₂(C₈H₈NO₂)₆(C₁₂H₈N₂)₂]_n, the Eu^III atoms are bridged by two tridentate, two bidentate and four mondentate carboxylate groups with an inversion centre between the two Eu^III ions of this dinuclear structural unit. Each Eu atom is nine-coordinated by two 1,10-phenanthroline N atoms and seven O atoms of four anilinoacetate ligands. In the crystal structure, the chains are linked by C—H...N and C—H...O hydrogen bonds into a polymeric ribbon structure.

In the crystal structure of the title compound, [Co(C₂H₄NO)(NO₃)(C₁₂H₈N₂)]_n, the Co^II atoms are linked by acetamidate ligands to form a chain. Each Co^II atom is five-coordinated by two N atoms of a 1,10-phenanthroline ligand, one nitrate O atom, and one N atom and one O atom of an acetamidate ligand within a trigonal-bipyramidal coordination geometry. In the crystal structure, the chains are linked by hydrogen bonds into a polymeric ribbon structure.

The crystal structure of the title compound, [Cu₆Br₆(C₅H₅NS)₄], consists of a hexanuclear Cu₆Br₆S₄ cluster in which each copper atom is connected to one bromine atom. The sulfur atoms are each connected to three copper atoms viaμ₃ coordination. Two of the bromine atoms are located on a twofold axis and the clusters are located on a fourfold rotoinversion axis. One unique Cu atom is disordered over two positions; site occupancy factors are 0.6 and 0.4. The other Cu atom is disordered about a twofold rotation axis.

In the title compound, {[Cu(C₇H₅O₂)₂(C₁₀H₁₄N₄O)]·H₂O}_n or {[Cu(BA)₂(BIE)]·H₂O}_n, where BA is the benzoate anion and BIE is 2,2′-bis(imidazolethyl), the Cu^II atom, which lies on an inversion centre, is coordinated in a square-planar geometry by two N atoms from two BIE ligands and two O atoms from two benzoate anions. The ether and water O atoms are located on twofold axes. The Cu^II atoms are linked via BIE ligands to form a one-dimensional chain structure along the c axis. The chains are further connected through hydrogen-bonding interactions between the water molecules and the carboxylate O atoms of the BA anions, resulting in a two-dimensional supramolecular network. The C atom and H atoms of the ethyl chain are disordered over two positions with refined occupancies of 0.583 (12) and 0.417 (12).

The title complex, [Ag₂(C₁₄H₈O₄)(C₇H₁₆N₂)₂]·2H₂O, consists of a biphenyl-4,4′-dicarboxylate-bridged centrosymmetric dinuclear silver(I) complex and two uncoordinated water molecules. The Ag atom is three-coordinated by two N atoms of 2-(piperidin-1-yl)ethanamine and one O atom of biphenyl-4,4′-dicarboxylate, forming a distorted T-shaped coordination environment, the distortion being caused by the strain created by the five-membered chelate Ag—N—C—C—N ring. In the crystal structure, molecules are linked through intermolecular N—H...O and O—H...O hydrogen bonds, forming layers parallel to the bc plane.

The title complex, {[Cu₂(N₃)₄(C₆H₁₆N₂)₂][Cu(N₃)₂(C₆H₁₆N₂)]}_n, consists of an end-on azide-bridged dinuclear copper(II) complex and an end-to-end azide-bridged polynuclear copper(II) complex. Each Cu atom is five-coordinated by two N atoms of N,N-diethylethane-1,2-diamine and by three N atoms from three azide ligands, forming a slightly distorted square-pyramidal coordination environment.

The centrosymmetric title complex, [Fe(C₂H₂N₉)₂(H₂O)₂]·2H₂O, has been prepared by an in situ [2+3] cycloaddition reaction of dicyanamide with sodium azide and ferrous sulfate, with heating and stirring. The Fe^II ion is coordinated by four N atoms from two 5-(1H-tetrazol-5-ylamino)-1H-tetrazolate ligands and two water molecules in axial positions in an octahedral geometry. The complex is linked into a three-dimensional network by O—H...N, N—H...O and N—H...N hydrogen bonds.

The crystal structure of the title compound, [Ba₂(CF₃O₃S)₂(C₁₂H₂₄O₆)₂(H₂O)₂](CF₃O₃S)₂, comprises a ten-coordinated Ba²⁺ cation that is coordinated by 18-crown-6, trifluoromethanesulfonate counter-ions and a water molecule, and an uncoordinated counter-ion. The dinuclear cation lies on a center of inversion. Each coordinated triflate group chelates a Ba atom while being monodentate to the adjacent Ba atom. The uncoordinated counter-ion is hydrogen bonded to the cation. Hydrogen bonds form infinite tubular arrays.

In the crystal structure of the polymeric title compound, {[Cu(C₇H₅N₂)₂(C₁₀H₈O₅)]·C₃H₇NO·5H₂O}_n, the 3-(4-carboxylatophenoxy)propionate dianion links the bis(benzimidazole)copper groups into a linear chain running along the a axis of the monoclinic unit cell, with the dianion binding through one O atom of each carboxylate end to confer a distorted square-planar environment on the copper center.

The Au atom in the title compound, [Au(CH₃)₂(C₁₃H₁₀NO)], has a square-planar coordination geometry. The molecule is located on a crystallographic mirror plane. The phenolate ring is disordered over two equally occupied positions. The molecules are packed in infinite stacks parallel to the b axis, with an Au...Au distance of 4.2106 (4) Å.

In the title compound, [Cu(C₁₂H₆N₂O₄)(H₂O)₂]_n, the 2,2′-bipyridine-3,3′-dicarboxylate (dcbp) dianion lies on a twofold rotation axis. The Cu atom also lies on this axis and is coordinated by two N atoms and two O atoms of two bridging dcbp ligands in the equatorial plane. Two aqua ligands complete the distorted cis-CuN₂O₄ octahedral coordination of the Cu atom. O—H...O hydrogen bonds help to stabilize the structure.

The title crystal structure, [Cu₃(C₂H₃O₂)₂(N₃)₄(C₂H₆OS)₂]_n, consists of one-dimensional chains in which there are two independent Cu^II ions. One of the Cu^II ions lies on a crystallographic inversion center and is in a slightly distorted octahedral coordination environment while the other Cu^II ion is coordinated in a distorted square-pyramidal environment.

In the title compound, {[Ni(C₁₆H₁₇FN₃O₃)₂]·2H₂O}_n, the Ni^II atom (site symmetry ) exists in a distorted trans-NiN₂O₄ octahedral geometry defined by two monodentate N-bonded and two bidentate O,O-bonded 1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylate (norf) monoanions. The extended two-dimensional structure is a square grid. N—H...O hydrogen bonds are present in the crystal structure. The water O atom is disordered over two positions; the site occupancy factors are ca. 0.77 and 0.23.

Redetermination of the structure of the title compound, K₂[Cu(C₇H₆N₂O₆)]·3H₂O, at 100 K reveals conformational disorder in the almost planar copper-containing molecular dianions and clarifies the complex hydrogen-bonded network involving the water molecules. The asymmetric unit contains two independent formula units. In one of the [Cu(C₇H₆N₂O₆)]²⁻ dianions, the propyl chain is disordered over two orientiations, with site-occupancy factors of 0.852 (5) and 0.148 (5).

The monoclinic (space group P2₁/c) title compound, [UO₂(CH₃O₃S)₂(H₂O)]_n, is a polymorphic modification of the known orthorhombic (space group Pbcn) variant of this stoichiometry [Wilson (1978). Acta Cryst. B34, 2302–2303]. The crystal structure consists of infinite [UO₂(CH₃SO₃)₂(H₂O)] chains along the a axis. The coordination polyhedron of the U atom is a pentagonal bipyramid, whose equatorial plane consists of the O atoms of four methanesulfonate anions and one water molecule. The axial positions are occupied by O atoms of a nearly linear and symmetrical uranyl group. The methanesulfonate anions function as bidentate bridging ligands. The crystal structure involves intermolecular O—H...O hydrogen bonds.

In the cation of the title compound, [Cu(C₁₂H₈N₂)₂(C₄H₈N₂O₂)](NO₃)₂·2H₂O, the Cu atom has a distorted octahedral coordination formed by six N atoms from one dimethylglyoxime and two 1,10-phenanthroline ligands. In the crystal structure, components are linked into a three-dimensional framework by O—H...O and C—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distance 3.592 (4) Å].

In the title complex, [Hg₂Cl₄(C₆H₁₈N₄)], one Hg^II ion is coordinated by four N atoms from a tris(2-aminoethyl)amine ligand and one Cl atom of a tetrachloridomercurate group in a distorted trigonal–bipyramidal geometry. The Cl atom occupies an axial position and bridges to a second Hg^II ion, which is coordinated in a distorted tetrahedral geometry by four Cl atoms. The bonds involving the bridging Cl atom are significantly longer than the other Hg—Cl bonds. In the crystal structure, molecules are linked by intermolecular N—H...Cl hydrogen bonds into a two-dimensional network, which is further stabilized by weak intermolecular C—H...Cl hydrogen bonds.

In the title compound, [Ni(C₂₂H₂₆N₂O₆)(H₂O)₂]·1.5H₂O, the Ni^II ion is in a slightly distorted octahedral coordination enviroment formed by an N₂O₄ donor set. In the crystal structure, intermolecular O—H...O and C—H...O hydrogen bonds and C—H...π interactions connect molecules into a three-dimensional network.

The title complex, [Rh(C₅H₇O₂)(C₁₇H₁₄NP)(CO)], adopts a square-planar geometry, with bite angles around the rhodium(I) centre varying between 85.28 (7) and 93.59 (8)°. The two phenyl rings and the one pyridine ring of the phosphine ligand are arranged in a face on/edge on orientation, with dihedral angles between the planes formed by these rings ranging between 66.55 (7) and 80.50 (7)°.

In the title compound, {[Cu(C₆H₆N₂O)₂(C₈H₄O₄)]·H₂O}_n, the Cu^II center exhibits a trans-CuN₂O₂ square-planar geometry arising from two O atoms of two benzene-1,2-dicarboxylate (bdc) dianions and two N atoms of two isonicotinamide molecules. The bdc dianions link the Cu centres into a zigzag chain. O—H...O and N—H...O hydrogen bonds generate a three-dimensional network.

In the title compound, [Cu(C₃H₂N₃O₂)₂(H₂O)₂], the Cu^II atom (site symmetry ) is coordinated by two N,O-bidentate 1H-1,2,4-triazole-3-carboxyate anions and two water molecules in a distorted trans-CuN₂O₄ octahedral arrangement. In the crystal structure, molecules are linked by intermolecular N—H...O and O—H...O hydrogen bonds.

In the title complex, [Ni(C₆H₄NO₃)₂] or [Ni(L)₂] (L = 2-pyridinecarboxylic acid N-oxide), the Ni atom occupies a crystallographic inversion center and is coordinated by four O atoms of two ligands L, giving a square-planar geometry. The O atom of the N-oxide is also engaged in a weak interaction with symmetry-related complexes [2.58 (3) Å] to form long Ni—O—Ni bridges, which extend parallel to the a axis. The stacking of the square-planar complexes is further stabilized by a slipped π–π interaction between the pyridine rings of adjacent molecules with a centroid-to-centroid distance of 3.3900 (7) Å and an interplanar distance of 3.099 (2) Å, resulting in an offset angle of 24°.

In the title compound, [CaI₂(C₄H₈O)(C₄H₁₀O₂)₂], the Ca atom is situated in the centre of a distorted pentagonal bipyramid. Two iodide anions occupy the axial positions, whereas the five oxygen donor atoms of two molecules of 1,2-dimethoxyethane and one molecule of tetrahydrofuran occupy the equatorial positions. The molecule is located on a crystallographic C₂ axis.

The title compound, (C₁₂H₉N₂)₃[Y(C₇H₃NO₄)₃]·C₂H₆OS·5H₂O or (phenH)₃[Y(pydc)₃]·DMSO·5H₂O (phenH is 1,10-phenanthrolinium, pydc is pyridine-2,6-dicarboxylate and DMSO is dimethyl sulfoxide), was synthesized by the reaction of YCl₃ with the proton-transfer compound (phenH)₂(pydc) in DMSO as solvent. The nine donor atoms of the three pydc²⁻ fragments form a distorted tricapped trigonal–prismatic arrangement around the Y^III centre. Considerable π–π and C—H...π stacking interactions between the aromatic rings of pydc²⁻ [centroid–centroid distances 3.659 (4) and 3.662 (4) Å], and between the CH groups of DMSO with the benzene rings of the pydc²⁻ fragments, are observed. In the crystal structure, a wide range of non-covalent interactions consisting of hydrogen bonding [of the types O—H...O, O—H...S, N—H...O and C—H...O], ion pairing, π–π and C—H...π stacking connect the various components into a supramolecular structure.

The centrosymmetric title compound, [Zn₂(C₂₂H₂₂N₄O₂)(C₄H₇O₄)₂], is a dinuclear zinc(II) complex. Each Zn^II atom has a square-pyramidal geometry with N₂O₃ donors, being coordinated by two N atoms and two O atoms from the 10,21-dimethyl-3,6,14,17-tetraazatricyclo[17.3.1^8,12]tetracosa-1(23),8,10,12(24),19,21-hexaene-23,24-diolate ligand and one O atom from a maleate anion. The two pentacoordinated Zn^II atoms are linked by two phenolate O atoms. This leads to the formation of a four-membered Zn₂O₂ ring. The molecule exhibits a strong intramolecular O—H...O hydrogen bond, with an O...O distance of 2.480 (2) Å.

The Ni^II atom in the title complex, [Ni(C₁₇H₁₇ClNO)₂], is tetracoordinated by two N atoms and two O atoms from two bidentate salicylideneiminate ligands, forming a square-planar environment. The asymmetric unit consists of two half-molecules; in each molecule the Ni atom lies on a centre of symmetry.

The crystal structure of the title compound, [NaNd(C₈H₁₁NO₅PS)₄]_n, is composed of two types of crystallographically independent polymeric chains, A and B, respectively, which are formed by alternating anions and sodium cations. In both polymeric chains, Nd^III ions are eight-coordinated by O atoms belonging to the sulfonyl and phosphoryl groups of four bidentate chelate ligands. In chain A, the coordination polyhedron of the Nd^III ion has a conformation intermediate between bicapped trigonal-prismatic and square-antiprismatic, and the Na^I ion is coordinated by two N and four O atoms in a distorted octahedral geometry. In chain B, the coordination polyhedron of Nd is a slightly distorted square antiprism, and Na is coordinated by four O atoms in a distorted tetrahedral geometry.

In the title compound, [Zn(SO₄)(CH₄N₂S)₃], the Zn²⁺ cation is coordinated in a tetrahedral geometry by one O atom from a sulfate anion and the S atoms from three thiourea ligands. There are weak N—H...O and N—H...S hydrogen bonds in the structure, some of which are bifurcated. The same crystal has also been investigated at 110 K, below a reported phase transition at 120 K. No change in the space group below 120 K was observed. On the other hand, the differences between the fractional coordinates of the corresponding atoms in the determinations at 292 and 110 K are as large as about 0.007 for the non-H atoms. Differential scanning calorimetry did not detect reproducible anomalies in the interval 93–503 K up to the melting point.

In the title complex, [Pb(C₁₄H₁₂N₂)(C₇H₅O₃)₂]·C₁₄H₁₂N₂·3H₂O, the Pb^II ion is coordinated by two N atoms from one 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand and four O atoms from two 3-hydroxybenzoate anions in a distorted pseudo-square-pyramidal environment, considering the dmphen molecule as an apical ligand. Molecules are linked into a three-dimensional framework through O—H...O and O—H...N hydrogen bonds. The crystal structure is further stabilized by π–π interactions between the dmphen rings of neighboring molecules, with a distance between the ring planes of 3.493 Å.

In the title compound, [Mn(C₇H₅O₃)₂(C₁₄H₁₂N₂)(H₂O)]·C₁₄H₁₂N₂·C₂H₆O·H₂O, the Mn^II ion is six-coordinated by two N atoms of a 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand, two carboxylate O atoms of one 4-hydroxybenzoate anion, one carboxylate O atom of another 4-hydroxybenzoate anion and one O atom of a water molecule. The resulting coordination geometry is a pseudo-square pyramid, considering the bidentate 4-hydroxybenzoate anion as an apical ligand. The separation between the Mn atom and the non-bonded carboxylate O atom of the monodentate benzoate anion is 3.520 (3) Å, much larger than the distance expected for an Mn—O bond. The crystal structure is stabilized through O—H...N and O—H...O hydrogen bonds involving the uncoordinated dmphen and the ethanol and water solvent molecules, and by π–π interaction between the uncoordinated and neighboring coordinated dmphen molecules, with a centroid–centroid separation of 3.812 (5) Å.

The title compound, [Co(C₁₁H₉F₃O₃)₂(C₅H₅N)₂], has an octahedral cobalt(II) centre. The crystal structure is stabilized by weak C—H...π interactions between a benzene H atom and a neighboring pyridine ring.

The title complex, [MnCl₂(C₇H₇N₂O)(C₇H₈N₂O)] or [MnCl₂{(py)C(Me)NOH}{(py)C(Me)NO}] (py is pyridyl), has been prepared by the reaction of (py)C(Me)NOH with MnCl₂. The metal ion is coordinated by a chloride ligand, an N,N′-chelating (py)C(Me)NOH molecule and a (py)C(Me)NO molecule. The six-coordinate molecule is the cis–cis–trans isomer considering the positions of the coordinated Cl atoms, pyridyl and oxime N atoms, respectively. There is an intramolecular O—H...Cl hydrogen bond. The molecules are linked by intermolecular C—H...O and C—H...Cl hydrogen bonds.

In the title compound, [Co(C₁₁H₁₂NO₂)₂], the Co^II atom, lying on a twofold rotation axis, is four-coordinated by two imine N and two phenolate O atoms from two Schiff base ligands in a distorted tetrahedral coordination gometry. The two Schiff base ligands are nearly perpendicular to each other, with a dihedral angle of 87.1 (2)° between their mean planes.

In the title compound, [Mn(NCS)₂(C₅H₅N)₄], the Mn atom lies on an inversion centre and assumes a distorted octahedral geometry defined by four N atoms from four pyridine molecules and two thiocyanate anions.

The title compound, [CdCl₂(C₆H₇N₃O)₂], was obtained unintentionally as a product of an attempted reaction of CdCl₂·2.5H₂O and picolinic acid hydrazide, in order to obtain a cadmium(II) complex analogous to a 15-metallacrown-5 complex of the formula [MCu₅L₅]X_n, with M = a central metal ion, L = picolinic acid hydrazide and X = Cl⁻, but with cadmium the only metal present. The coordination geometry around the Cd^II atom can be considered as distorted octahedral, with two bidentate picolinic acid hydrazide ligands, each coordinating through their carbonyl O atom and amino N atom, and two chloride anions. In the crystal structure, intermolecular N—H...Cl and N—H...N hydrogen bonds link the molecules into a two-dimensional network parallel to the (100) plane. The pyridine rings of adjacent networks are involved in π–π stacking interactions, the minimum distance between the ring centroids being 3.693 (2) Å.

The anionic part of the title compound, (C₆H₁₆N)[Re(C₂O₄)₂O(C₁₈H₁₅P)], is a substituted derivative of trans-trichloridooxidobis(triphenylphosphane)rhenium(V) with oxalate. In the structure of the anion, an oxidorhenium(V) unit defines a molecular axis in a distorted octahedral coordination about the central atom. The second axial position is occupied by an O atom of one of the chelating oxalate ligands. The distances of the oxalate O atoms to the central Re atom vary from 2.003 (3) to 2.092 (3) Å, the longest bond being the one trans to the oxide ligand. The anions and cations are connected by a bifurcated hydrogen bond from a triethylammonium NH donor to two oxalate O-atom acceptors.

The title compound, [Sn(C₆H₅)₂(C₁₅H₁₁ClN₂O₃)], crystallizes with two independent molecules in the asymmetric unit with almost identical conformation. In each molecule, the Sn atom is coordinated by two O, one N and two C atoms in a distorted trigonal–bipyramidal geometry [Sn—O = 2.066 (3)–2.132 (4) Å, and Sn—N = 2.150 (4) and 2.141 (4) Å].

The title compound, [Cu₂(C₁₀H₂O₈)(H₂O)₄]_n, is isostructural with the analogous Zn polymeric compound [Wang, Lu, Yang, Zhao & Ng (2007). Acta Cryst. E63, m2986]. Each Cu^II ion is coordinated by five O atoms [Cu—O = 1.968 (2)–2.268 (3) Å] in a trigonal–bipyramidal geometry. The coordinating water molecules are involved in intermolecular O—H...O hydrogen bonds [O...O = 2.726 (3)–2.767 (3) Å], which consolidate the packing.

In the title heteronuclear Ni^II–Sm^III complex (systematic name: {6,6′-diethoxy-2,2′-[ethane-1,2-diylbis(nitrilomethylidyne)]diphenolato-1κ⁴O¹,O¹',O⁶,O⁶':2κ⁴O¹,N,N′O¹′}trinitrato-1κ⁶O,O′-samarium(III)nickel(II)), [NiSm(C₂₀H₂₂N₂O₄)(NO₃)₃], with the hexadentate Schiff base compartmental ligand N,N′-bis(3-ethoxysalicylidene)ethylenediamine (H₂L) the Ni and Sm atoms are doubly bridged by two phenolate O atoms provided by the Schiff base ligand. The coordination of Ni is square planar with the donor centres of two imine N atoms and two phenolate O atoms. The samarium(III) centre has a decacoordination environment of O atoms, involving the phenolate O atoms, two ethoxy O atoms and two O atoms each from the three nitrates. Some weak C—H...O and O...Ni [3.381 (4) Å] interactions generate a two-dimensional zigzag sheet.

In the title complex, [Mn(C₂₂H₁₈N₂O₄)Cl(CH₃OH)], the Mn^III centre is in a distorted octahedral geometry, with the N₂O₂ tetradentate Schiff base ligand in the equatorial plane and the chloride ion and methanol molecule in the axial positions. The dihedral angles between the two outer phenolate rings and the central benzene ring of the tetradentate ligand are 4.08 (14) and 13.61 (14)°. One of the two methoxy substituents on the outer phenolate rings lies almost in the plane of the ring to which it is bound, whereas the other methoxy group is twisted significantly from the corresponding benzene ring plane. In the crystal structure, weak intermolecular C—H...Cl interactions link the molecules into infinite chains along the b axis, and these chains are further connected by O—H...O hydrogen bonds, weak C—H...O and C—H...Cl interactions into sheets parallel to the ab plane. The crystal structure is further stabilized by C—H...π interactions.

In the salt (C₈H₂₀N)[ReBr(C₇H₂Br₃O₂)(CO)₃], the bromidotricarbonyl(tribromotropolonato)rhenate(I) anion interacts with adjacent anions through intermolecular bromido–bromido interactions [3.2675 (5)–3.4962 (4) Å]. The Re^I atom shows octahedral coordination. The crystal structure also involves C—H...O and C—H...Br interactions.

The title compound, [Cu(C₁₆H₁₉N₂O)(N₃)], was synthesized by the reaction of equimolar quantities of 2-hydroxy-1-naphthaldehyde, N-propylethane-1,2-diamine, sodium azide and copper(II) acetate in a methanol solution. The Cu^II ion in the compound is four-coordinated by one imine N, one amine N, and one phenolate O atoms of the Schiff base ligand 1-[2-(propylamino)ethyliminomethyl]naphthalen-2-ol and by one terminal N atom of an azide anion, forming a square-planar coordination. The propyl group and attached NH are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.

The monomeric organotin(IV) carboxylate [Sn(C₄H₉)₂(C₈H₈NO₂)₂] has four molecules in the asymmetric unit. The Sn atom exists in a six-coordinated skew-trapezoidal environment in which the carboxylate group chelates in an anisobidentate manner. In one molecule, one of the butyl groups is disordered; the site occupancy factors are ca 0.7 and 0.3. In all four molecules, the methylamino substituents are slightly twisted from the mean planes of the phenylene rings, with dihedral angles of 13.43 (13), 11.34 (12), 14.92 (11) and 11.10 (12)°. The crystal structure is stabilized by N—H...O hydrogen bonds and C—H...π interactions. In the crystal packing, the molecules are arranged into chains along the [010] direction. Neighbouring chains are arranged in a T-shaped manner. The crystal structure is an inversion twin.

In the title complex, [Zn(C₄₈H₃₆N₄O₄)]·C₂H₂Cl₄, the Zn^II ion is located on an inversion centre and in an approximately square-planar coordination environment. The tetrachloroethane solvent lies across an inversion centre at the mid-point of the C—C bond. Porphyrin–porphyrin and porphyrin–solvent contacts are dominated by C—H...π and C—H...O interactions, resulting in the formation of a clathrate-like structure. One benzene ring and its methoxy substituent are disordered over two positions, with site occupancies of 0.824 (2) and 0.176 (2). In addition, two symmetry-equivalent Cl atoms of the tetrachloroethane solvent also exhibit positional disorder, with site occupancies of 0.635 (2) and 0.365 (2).

In the title compound, {[Cu(C₇H₃NO₄)(H₂O)₂]·0.625H₂O}_n, square-pyramidally coordinated Cu^II atoms with two cis-aqua ligands are linked into linear chains by bis-bridging pyridine-2,4-dicarboxylate (PDC) dianions. The [Cu(PDC)(H₂O)₂]_n chains form ribbons through long-range Cu—O interactions; the ribbons aggregate into a three-dimensional network through hydrogen bonding. The two uncoordinated water molecules of the asymmetric unit (one with partial occupancy) lie on different special positions of site symmetry 2.