European Journal of Inorganic Chemistry

Four new helical metal–organic frameworks have been synthesized by using 3-[4-(carboxymethoxy)phenyl]propanoic acid ligands and Zn^II, Cd^II, Co^II, and Ni^II salts. The shapes of the helical chains include single-screw, lemniscate, and tetraflexural helices, and their photoluminescence and magnetism are investigated.

The synthesis and immobilisation of a series of ruthenium and osmium compounds with novel pyridine and thiophene linking groups are reported. The monolayers are studied both electrochemically and by surface-enhanced Raman spectroscopy.

A metalloenzyme consisting of a Rh-based catalytic head and a fatty acid derived tail bound to β-lactoglobulin catalyzes the asymmetric transfer hydrogenation of a ketone with an enantiomeric excess (ee). Calculations based on the crystal structure reported here show that the complex head can adopt discrete orientations, which may explain the ee.

A uranyl hybrid compound with urea-bearing dipropionic acid as a well-designed ligand is prepared. The urea group plays a role in coordination and in hydrogen-bonding interactions. The uranyl ion can be selectively complexed and precipitated by this urea-bearing ligand from alkaline spring water in the presence of competing metal ions.

Sulfur-substituted alkynes show contrasting behaviour in their reactions with Ti^II and Co^I. Whereas the Ti^II centre in the titanocene η²-alkyne complex effects a cleavage of the alkyne C_sp–S bond concomitant with C–C coupling, Co^I in the [Co(triphos)] η²-alkyne complex leads to loss of the benzyl groups to give either a heterobimetallic Co/Ru acetylene dithiolate complex or a dithiolene complex.

The binding between fluorinated zinc porphyrins and site-differentiated [4Fe–4S] clusters through pyridyl- and imidazolylthiolate bifunctional bridging ligands generates catalytic arrays inspired by the active site of sulfite reductase. The properties of the unique [4Fe–4S] clusters applied here are described, and binding constants are reported for the two components of the resulting macromolecular scaffold.

The complex Na₂{trans-[PdCl₂(mTPPMS-κP)₂]} (1) reacts with 8-TTH to give the polymer trans-{Pd-μ-[mTPPMS-1κP:2κO-Na_1/2(H₂O)]-μ-[mTPPMS-1κP:2κO′-Na′_1/2(H₂O)]-μ-[8TTH-1κS:2κO6-Na_1/2(H₂O)]-μ-[8TTH-1κS:2κO6-Na′_1/2(H₂O)]}_n (3) {mTPPMS = Ph₂P[3-OS(O)₂C₆H₄]^–; 8-TTH = 8-thiotheophyllinate}. Their activity towards DNA was studied.

Herein, we report the synthesis of a new ligand with two adjacent pyrazole–pyridine units and its dinuclear cobalt(II) and zinc complexes as well as a trinuclear zinc complex. The reactivity of these complexes with dioxygen is investigated.

Paints containing alkyd resins need catalysts for oxidative curing. Because of the probable reclassification of the widely used cobalt carboxylates as carcinogens there is interest in alternative alkyd paint drying catalysts. Various manganese and iron paint driers with polydentate ligands have recently been reported; a particular iron-based catalyst shows good paint drying activity at low dosage.

Complexes with the general formula [Fe(4-bphz)₂(NCS)₂]·X [4-bphz = 1,2-bis(pyridin-4-ylmethylene)hydrazine, X = guest molecules] are composed of isomeric 2D gridlike networks, but show different solvation polymorphs. Whether the complex undergoes spin crossover or is just paramagnetic depends on both the inclusive guest molecules and the conformation of the ligands.

Diketiminate-supported iron and cobalt complexes react with activated magnesium in tetrahydrofuran (THF) to give complexes with M–NN–Mg–NN–M (M = Fe, Co) cores. The Mg ion prefers to bind end-on to N₂, which contrasts with the side-on binding of N₂ by sodium and potassium ions in previous complexes.

Aromatization-driven acid-catalyzed condensations of the N,P-diprimary compound 1 with dialdehydes are coupled with hydrogen transfer reactions. With glyoxal and pyridine-2,6-dicarbaldehyde this gives rise to side products, but with o-C₆H₄(CHO)₂, high yields of 4 are obtained. π-Delocalization through the coplanar aryl rings causes high π-density at the phosphorus atom.

Treatment of BeCl₂ with dry liquid ND₃ and subsequent removal of the solvent leads to a colourless microcrystalline powder of [Be(ND₃)₄]Cl₂.

We review our results concerning the relative orientation of the anion and cation and the characterization of the carbon–gold bond in the first intermediates (L–Au–S)⁺X^– (L = NHC carbenes and phosphanes, S = alkenes and alkynes, X^– = weakly coordinating counterion) formed during nucleophilic attack on unsaturated systems.

Coordination versus bond activation of several X–H substrates was studied by DFT calculations for SCS pincer palladium complexes featuring methanediide and indenediide backbones.

Three heteroleptic ruthenium hydride complexes [Ru(PCy₃)(ZnCp*)₂(ZnMe)₆] (Cp* = pentamethylcyclopentadienyl), [Ru(PPh₃)₂(ZnCp*)₂(ZnMe)₂(H)₂], and [Ru(PCy₃)₂(ZnMe)₂(μ₂-H)₄] have been synthesized and characterized by NMR and IR spectroscopy, MS analysis, single-crystal X-ray diffraction, and elemental analysis. The influence of the phosphane ligand on the product formed is discussed.

Despite their toxicity, organoselenium compounds are important for their potential application in disease prevention. The antioxidant activity of a small organoselenium compound is investigated by DFT and explicit solvation models that facilitate proton exchange.

The reactions of low-valent six-membered β-diketiminate–gallium(I), Ga(DDP) [DPP = HC(CMeNC₆H₃–2,6-iPr₂)₂], with [Cp*Ru(μ-H)₂]₂ (Cp* = pentamethylcyclopentadiene) and [(η⁶-p-cymene)RuCl₂]₂ lead to [(Cp*Ru)₂(μ-H)₂{μ-Ga(DDP)}] (3) and[(η⁶-p-cymene)Ru(DDP)Ga(µ-Cl){Ga(Cl)(N{C₆H₃iPr₂})₂(µ²-CH₂C₄H₅)}] (6), respectively. Compound 6 is a cycloruthenated product formed by an intramolecular C–H bond cleavage reaction.

The CH₃CN/CD₃CN exchange at the trans-to-oxido sites in the bis(μ-acetato)(μ-oxido)diruthenium(III) complex cation takes place in CD₃CN through a dissociative or dissociative–interchange mechanism. The activation mode of the substitution of pyridine derivatives (Rpy) for coordinated CH₃CN in CH₃CN shifts from a dissociative interchange to an associative interchange, depending on the electron-donating ability of Rpy.

Three-dimensional network mesoporous nanostructured α-MnO₂ with a high specific surface area and narrow pore size distribution has been fabricated in high yields without a template at room temperature.

A series of polynuclear copper(I) thiolate clusters were synthesized and characterized by single-crystal X-ray diffraction. All of them show significant luminescence in the solid state. Intensity and wavelength of the emitted light strongly depend on the molecular structures of the compounds.

The nitridoiridium complex [Ir(N){N(CHCHPtBu₂)₂}]PF₆ is oxidized by elemental sulfur and selenium to the corresponding thionitrosyl and selenonitrosyl complexes to give access to a rare example for a full M(NE) (E = none, O, S, Se) series. Bonding is discussed on the basis of crystallographic and spectroscopic characterization.

Heteronuclear lanthanide coordination polymers are synthesized and characterized. Solid-state NMR spectroscopy confirms the hypothesis of randomly distributed lanthanide ions. The spectroscopic and colorimetric properties are investigated. The resulting data demonstrates that this series of compounds presents highly tunable luminescence properties.

Competition and interplay between redox and coordination reactions in mixtures of redox-active guanidines and silver dicyanamide lead to new precursors of C,N materials and coordination polymers.

SmI₂(THF)_n as well as its reactivity towards benzophenone have been studied by means of DFT calculations. Preliminary results establish the speciation of SmI₂ in THF, quantify the lability of ligands and assess the energetics of reduction of the ketone. We show that [(THF)_nI₂Sm(μ-OCPh₂)]₂ is unlikely to be on the pathway of pinacol coupling due its high energy.

Kinetic measurements of CO₂ insertion into the Ru–H and Ru–Me bonds of trans-Ru(dmpe)₂(X)R [R = H, Me; dmpe = 1,2-bis(dimethylphosphino)ethane] have shown that these processes are sensitive to the electron-donating ability of X, and poorly electron-donating X ligands have a negative impact. Computational studies of reaction barriers and reaction enthalpies support these observations.

A monoiron(II) complex of 1,3-bis(2′-pyridylimino)isoindoline reacts with H₂O₂ to form a green diiron(III) peroxido intermediate, which may serve as the precursor to the active oxidant in thioanisole and benzyl alcohol oxidation.

The cis-α isomers of dioxidomolybdenum complexes with a chiral backbone exhibit higher catalytic epoxidation activity than the related cis-β complexes.

By utilizing chiral auxiliaries, a practical strategy for the generation of enantiomerically pure bis-cyclometalated Ir^III complexes was developed. The method relies on the synthesis and subsequent chromatographic separation of diastereomeric complexes followed by substitution of the auxiliaries with polypyridyl ligands with complete retention of configuration.

The hydroboration of a diphenylphosphanylenyne with Piers' borane at elevated temperature gives a zwitterionic borata–alkene. This unique reaction yields borata–alkenes without the need of α-boryl deprotonation.

Both large-sized mesopores and long-range ordering are realized in titania thin films by precisely controlling the properties of the precursor solution. The mesostructural domains successfully extend up to the micrometer scale, which, to the best of our knowledge, has never been seen in previous reports.

Cobalt and zinc compounds with 1,3,5-triaza-7-phosphaadamantane (PTA) derivatives and/or 1,10-phenanthroline-5,6-dione (DION) have been synthesized, characterized and screened against several human tumour cell lines. The DION-containing compounds exhibit specificity for the human fibroblast.

Two active Mg alkoxides have been incorporated into two bulky Al tetraphenolates and the helical complex 2 used to initiate the ring-opening polymerization (ROP) of L- and rac-lactide, leading to polymers with good molecular weight control and narrow molecular weight distributions. An overall rate expression of –d[lactide]/dt = k[lactide][complex] for the ROP of L-lactide was deduced.

A variety of new N-heterocyclic carbene (NHC) organozinc adducts are synthesized and characterized, among which are the first examples of NHC-stabilized zinc organocations. The NHC–Zn(C₆F₅)₂ adducts and BnOH/Zn(C₆F₅)₂ are effective ring-opening polymerization (ROP) initiators of cyclic esters/carbonates under mild conditions.

The bis(thiosemicarbazone) ligand glyoxalbis(4-methyl-4-phenyl-3-thiosemicarbazone) is shown to be a selective fluorescence “turn-on” sensor for zinc and is able to image intracellular zinc in MCF-7 breast cancer cells. This sensor is easy to synthesize, exhibits excellent sensitivity and selectivity towards Zn²⁺ over other physiologically relevant cations, and has sub-nanomolar binding affinity.

η⁵-Pentamethylcyclopentadienyltitanium sulfide clusters [(Cp*Ti)₄S₆] (1) and [(Cp*Ti)₆S₈] (2, Cp* = η⁵-C₅Me₅) are formed by sunlight photolysis of decamethyltitanocene dihydrosulfide [Cp*₂Ti(SH)₂] in toluene in 50 and 3 % yield, respectively. Both crystal structures are toluene solvates and are based on a nearly regular titanium octahedron for 2 and a trigonal pyramid for 1.

Five new copper(II) complexes derived from the anionic forms of phosphonoacetic acid are prepared. Four of these complexes are polynuclear copper(II) complexes, in which the above-mentioned anionic ligands act as bridging ligands in different coordination modes, and the other is a mononuclear compound. The magnetic behavior of the polynuclear compounds is studied.

The interaction between a 3d metal ion and Gd is antiferromagnetic if the 3d ion has no electron in its d orbital, as evidenced by the dinuclear Mn^III–Gd complex. This is in contrast to the ferromagnetic behavior of dinuclear Mn^II–Gd complexes for which the 3d orbital of Mn^II is singly occupied. This result agrees with our hypothesis initially based on Co^II_{low spin}–Gd vs. Co^II_{high spin}–Gd complexes.

Treatment of water with periodate in the presence of [IrCp*(Me₂NHC)(OH)₂] results in formation of O₂. DFT calculations and in situ mass spectrometry experiments point to a mechanism involving one or two O-atom-transfer steps, rather than electron-transfer steps only. Results must thus be interpreted cautiously when periodate is used as an oxidant in the study of catalytic water oxidation.

β-AgIO₃ is the first iodate phase obtained under high pressure. The reconstructive phase transition from the α-AgIO₃ acentric phase to the dense β-AgIO₃ centric phase is an endothermic transformation that occurs at 260 °C at 2.7 GPa.

The macrocycle complex [(Py₂N₂)Mn(H₂O)₂]²⁺ catalyses H₂O₂ disproportionation in aqueous solution, achieving large turnover numbers and operating over a wide pH range. Mechanistic studies implicate a monomeric catalyst for H₂O₂ disproportionation.

The easy access at room temperature to a monocarbonyl–Pt⁰ complex source allows the addition of stoichiometric amounts of MeI and the formation of acetone, while a Pt^II carbonate complex forms in the presence of O₂. Structural insights into the reaction products and calculated mechanisms are reported.

Diamagnetic [Cp′Fe(η³-BH₄)] can be converts cleanly to the trimeric [Cp′FeBH₂]₃ and H₂ at ambient temperature. DFT computations were used to rationalize the bonding in these molecules.

Hierarchical nanostructured Al-doped ZnO (AZO) powders were successfully prepared through a mild solution route. The optical and electrical properties of AZO vary with the Al doping contents. An Al content of 1.0 at-% was the optimum dopant to obtain the lowest electrical resistivity.

η⁵-Monocyclopentadienyliron(II)/ruthenium(II) complexes with 5-[3-(thiophen-2-yl)benzo[c]thiophenyl]thiophene-2-carbonitrile as ligand have been synthesized. Quadratic hyperpolarizabilities in the range of (105–164) × 10^–30 esu were evaluated by hyper-Rayleigh scattering at 1500 nm. DFT calculations were performed to explain their non-linear optical properties.

Of the various nickel(II) complexes with thiosemicarbazones [(2-OH-5-R¹-C₆H₃)C(R²)=NNHC(=S)NHR³], complexes 2 (R¹, R² = H; R³ = Me) and 3 (R¹, R² = H; R³ = Et) display fluorescent behavior. Interestingly, 2 shows double-photon emission.

The oxygen-vacancy-induced room-temperature 1D ferromagnetic semiconductor K₂V₆O₁₆·1.5H₂O composed of superlong nanobelts was synthesised, providing a new promising candidate for fabricating spintronic nanodevices in the future.

A series of oxo–tungsten(V) tetraphenylporphyrin complexes of the general formula [W^VO(TPP)X] [where TPP = dianion of 5,10,15,20-meso-tetraphenylporphyrin and X = –4-ClBz (p-chlorobenzoate) (1), –OH (2), –OMe (3), –Cl (4), –Br (5), or –NCS (6)] are synthesized. The complexes are characterized by different spectroscopic techniques, electrochemical studies, and single-crystal X-ray structure analysis.

During the synthesis of the sodium salt of double-decker octaphenylsilsesquioxane tetrasilanolate in 2-propanol, sodium isopropoxide is formed, which leads to the formation of unexpected cis- and trans-di[(3-chloropropyl)isopropoxysilyl]-bridged double-decker octaphenylsilsesquioxanes after in situ coupling with 3-chloropropyltrichlorosilane.

New ionic liquids containing lanthanide thiocyanates are prepared and characterized by spectroscopic and electrochemical techniques.

A two-electron-reduced dinuclear Ir^II–Ir^II complex was synthesized by the reaction of a mononuclear Ir^III aqua complex by extraction of electrons from H₂ in water under ambient conditions.

The influence of different countercations on the structural and spectroscopic properties of Nd³⁺ complexes with ethylenediaminetetraacetic acid (EDTA) and its phosphonate analogue ethylenediaminetetramethylenephosphonic acid (EDTMP) are discussed. The absence of water molecules in the inner coordination spheres of the Nd³⁺ ions in the phosphonates is a reason for the efficient near-IR (NIR) f–f luminescence of the Nd³⁺–EDTMP crystals.

The emission efficiency of CdSe-type quantum dots in organic solution is affected by the addition of the electron acceptor tetracyanoethene. The latter can both react with the alkylamine capping ligands at the surfaces of the nanocrystals and dynamically quench the quantum dot emission. This behavior is exploited to encode NAND and XOR Boolean logic operations with a luminescence output.

In a unique conversion, copper(II) and nickel(II) hydroxide complexes supported by a sterically unhindered pyridyl(dicarboxamide) ligand react with CH₃CN to yield cyanomethide complexes. Oxidations of the Cu^II–OH and –CH₂CN species are also explored.

New mixed κN,κS mono- and tri-armed bidentate ligands, characterized by a pyridinyl/sulfinyl upcoming arrangement, have been efficiently prepared and fully characterized including by single-crystal X-ray diffraction. The successful chelation of square planar platinum(II) complexes opens the way to promising applications in the preparation of supramolecular organometallic frameworks.

The effects of size, pressure and interactions on 3D spin crossover systems within the framework of an Ising-like model are discussed.

The reactivity of a redox-active thorium(IV) complex with CH₃I and Me₃SiI is shown to be divergent. This is a rare example of the use of redox-active ligands with the actinides.

To find new coordination and supramolecular assemblies, the structure inducer anions [ZnCl₄]^2– and [CdCl₄]^2– were introduced into alkali metal/pentacyclohexanocucurbit[5]uril (alkali-PCyHQ[5]) systems. These anions did not show the typical “honeycomb effect”, but played the role of linkers in the construction of alkali-PCyHQ[5]-based supramolecular chains.

Chiral phenanthro-annulated imidazolium salts were prepared from 9,10-phenanthrenequinone and 1-phenylethylamine and converted to N-heterocyclic carbenes. Ag^I complexes were obtained by reaction of the imidazolium salts with Ag₂O and used for transmetalation with [RuCl₂(C₆H₆)]₂. Both the Ag^I and the Ru^II complexes showed restricted flexibility in solution.

A new structure type containing layers parallel to (001) built up from Si₃O₁₀ groups and Co₂O₁₀ dimers was determined to be the trisilicate CoEu₂Si₃O₁₀. Light violet monoclinic crystals were obtained by using a high-temperature flux-growth method.

Zintl-type P₇^3– complexes were synthesized from direct activation of P₄ by lanthanum and lutetium naphthalene complexes. The P₇^3– complexes showed fluxional behavior dependent on the rare-earth metal.

Mo carbonyl complexes with mixed N-heterocyclic carbene (NHC)/phosphane ligands and those with pure NHC and phosphane ligands are compared. Whereas the σ-donor strengths of phosphane and carbene groups are comparable, the π-acceptor interactions of the carbene moieties are exactly canceled by π-donor interactions.

Oxidation of (IP^–)₂Al(CH₃) (IP = iminopyridine) with TrBPh₄ (Tr = trityl) affords the C–C-coupled kinetic product [(IP)(Tr-IP)Al(CH₃)][BPh₄] in which the trityl radical and the IP^– radical have undergone C–C bond formation. Oxidation of (IP^–)₂Al(CH₃) with TrBArF₂₄ affords the thermodynamic product [(IP)(IP^–)Al(CH₃)][BarF₂₄] {BArF₂₄ = tetrakis[(3,5-trifluoromethyl)phenyl]borate}.

Cationic copper(I) complexes containing two triazolylidene carbenes of the abnormal type are shown to be excellent catalysts for the [3+2] cycloaddition reaction between azides and alkynes. A range of azides and a couple of alkynes are activated by these copper(I) complexes towards the catalytic formation of the corresponding substituted 1,2,3-triazoles.

The transformation of V^III azides to the corresponding V^V nitrides was investigated through isotopic labeling crossover experiments, SQUID magnetization, and multifrequency/high-field EPR studies. While Lewis bases inhibit the azide-to-nitride transformation, nitride complexes are formed by a bimetallic mechanism. Stoichiometric Lewis acid and catalytic amount of V^II complex also rendered azide-to-nitride formation. However, Lewis bases inhibit formation of nitride product.

A highly reactive phosphanylamide-supported Zr/Co complex has been shown to react with alcohols, thiols, peroxides, and disulfides by means of a dissociative electron-transfer process occurring at Zr. A range of products are formed depending on the identity of the substrate, including both one- and two-electron oxidized products.

Dioxomolybdenum(VI) complexes with acylpyrazolonate ligands have been synthesized, characterized, and tested as catalysts in the deoxygenation of styrene oxide with triphenylphosphane as the oxygen acceptor.

Chiral tetradentate dianionic ligands of the diamine-diphenolato and diamine-diolato families based on the (R,R)-2,2′-bipyrrolidine core led to chiral-at-metal complexes of the type [{ONNO}Zn] as single diastereomers supporting a predetermined chiral induction from the bipyrrolidine core to the helical ligand wrapping.

New synthetic routes to a series of bis(pentafluoroethyl)phosphanes have been developed and the structures of two of them, (C₂F₅)₂PH and the phosphinous acid (C₂F₅)₂POH, were studied by gas electron diffraction, making use of molecular dynamics calculations to support data analysis in an improved approach.

Two polyoxopalladates {Pd₁₂X^III} have been synthesized by using Cr³⁺ and In³⁺ ions as structural directing agents. The coordination configuration of the central metal ions influenced by their ionic radii can affect the cluster stability, as shown by their collision-induced dissociation MS/MS spectra. This approach may help us to understand the stability and dissociation of polyoxopalladates.

Thermal or photodecomposition of 2,2′-azobis(2-methylpropionitrile) (AIBN) is used as a source of cyanide anions in the synthesis of copper(I)–cyanide frameworks. The reported methodology utilizes the direct reduction of Cu^II(aa)(NN)X (aa = deprotonated amino acid, NN = bidentate nitrogen-based ligand, X = Cl or Br) complexes by AIBN/ascorbic acid to yield six novel coordination networks.

{Pyrenetetrasulfonate(PyTS)/ZnS}_n ultrathin films have been fabricated by a two-step procedure of layer-by-layer assembly of PyTS with Zn₂Al layered double hydroxide, followed by in situ sulfurization with H₂S. Gas-sensing measurements of the as-prepared (PyTS/ZnS)_n films indicate that they selectively respond to ethanol gas at a relatively low temperature of 70 °C.

YAH: Alkyl/hydrido exchange readily takes place when the yttrium methyl complexes (C₅Me₅)₂YMe(thf), [(C₅Me₅)YMe₂]₃, and [YMe₃]_n are treated with the amidoalane HAl[N(SiMe₃)₂]₂. The resulting heterobimetallics catalyze the addition of the amidoalane across 1-octene, as shown for (C₅Me₅)₂Y(μ-H)₂Al(Me)[N(SiMe₃)₂].

A novel synthetic route to terpyridine ligands is reported. Pyridine building blocks are interlinked by Suzuki–Miyaura cross-coupling reactions. The potential of the method is demonstrated by assembling the 4,4″-disubstituted terpyridine ligands shown, which are subsequently converted into their homoleptic Fe^II complexes.

The N,N-trans and N,N-cis isomers of [Ir(ppy⁰)₂(PP)]⁺ (ppy⁰ = 2-phenylpyridine ligand, PP = diphosphane ligand) have markedly different photophysical properties, which were investigated by a DFT/time-dependent DFT (TD-DFT) approach. Their different quantum phosphorescence efficiencies (Φ_PL) are interpreted with their different radiative (k_r) and nonradiative (k_nr) rates.

New halido-bridged mixed-valence Cu^I–Cu^II coordination polymers with 1D infinite chain structures have been synthesized and structurally characterized The complexes show a relatively strong antiferromagnetic interaction and interesting semiconducting behavior. These coordination polymers were applied as sensitizing materials for DSSCs.

Cobalt diglyoximate complexes connected by aluminum bridges were synthesized. The redox chemistry of these species is dependent on the number of aluminum centers and the nature of the ancillary ligand coordinated to aluminum. Proton reduction to hydrogen was observed and compared to BF₂- and proton-bridged analogs.

The insertion of CO₂ into iridium hydrides has been proposed as a crucial step in the iridium-catalyzed hydrogenation of CO₂. We used DFT to explore the mechanism of CO₂ insertion into five-coordinate iridium(III) dihydrides and four-coordinate iridium(I) monohydrides with pincer ligands, and also calculated the catalytic cycle for thermal CO₂ hydrogenation starting from an iridium(III) dihydride.

The niobium nitride complex prepared from N₂ was protonated to generate NH₃, while the reaction with methyl iodide gave the methyl imide complex. Exposure of the imide complex to CO₂ gave the ureate complex along with the oxo-bridged dinuclear complex.

The symmetry-forbidden cyclometalation of (silox)₂W=N^tBu (1, silox = OSi^tBu₃) to (silox)(^tBuN)W(H)(κO,κC-OSi^tBu₂CMe₂CH₂) (2) and the oxidative addition of dihydrogen to give (silox)₂(^tBuN=)WH₂ (3) are catalyzed by phosphane bases with cone angles < 160°. Quantum mechanics/molecular mechanics (QM/MM) calculations support the experimental findings and show that Lewis bases promote σ/π mixing.

The two-electron reduction of the phosphaalkyne tBuC≡P by the U^III mixed-sandwich complex [U(η⁵-C₅Me₅){η⁸-C₈H₄(SiiPr₃)₂}] yields the diuranium(IV) product [(U{η⁵-C₅Me₅}{η⁸-C₈H₄(SiiPr₃)₂})₂(μ-tBuCP)], which contains a μ-η²:η¹-ligated phosphaalkene dianion.

Tetranuclear [Ln(Me₃TACD)(μ-H)₂]₄ [Ln = Ce (1-Ce), Pr (2-Pr)] and dinuclear [Ln(Me₃TACD)(η³-C₃H₅)(μ-H)]₂ [Ln = Nd (3-Nd), Sm (4-Sm)] have been obtained by treatment of the corresponding bis(allyl) Me₃TACD complexes with phenylsilane and were tested as catalysts in the copolymerization of cyclohexene oxide with CO₂.

The selective, catalytic semihydrogenation of alkynes by group 5 imido and bis(imido) complexes is presented from synthetic and mechanistic perspectives in the context of previous stoichiometric studies on the d⁰ metal–ligand multiple-bond activation of strong σ bonds and both stoichiometric and catalytic studies on H₂ activation and hydrogenation by d² group 5 complexes.

The lipophilic dendritic ligand L6 selectively reacts with trivalent yttrium hexafluoroacetylacetonate (hfac) to give the liquid-crystalline single-stranded dinuclear helicate [Y₂(L6)(hfac)₆], which self-organises into an SmA mesophase.

The new Ru₂ azido complex [Ru₂(chp)₄N₃] (chp = 2-chloro-6-hydroxypyridinate) reacts with PPh₃ under photolytic conditions to form [H₂NPPh₃]⁺Cl^– and [Ru₂(chp)₄Cl], from which the azide complex can be regenerated.

The outcome of the reaction between TEMPO and MBr₃ (M = B, Al) was found to depend on the Lewis acidity of the group 13 element. Addition of TEMPO to AlBr₃ results in formation of the 1:1 adduct, AlBr₃(η¹-TEMPO). In contrast, addition of TEMPO to BBr₃ results in TEMPO disproportionation and formation of [TEMPO][BBr₄] and (TEMPO)₂BBr.

The electronic effects that dictate the binding of small molecules to a [Fe]-hydrogenase mimic are examined by DFT computations. Analysis reveals that a ligand's ability to donate electron density to the Fe centre determines the overall reaction free energy.

A (β-diketiminato)nickel hydrazido(1–) complex has been synthesized that acts as a four-electron reductant towards a diazene: The corresponding hydrazine is formed, as well as a novel trinuclear complex with bridging hydrazido(2–) ligands, which can also be obtained through activation of the diazene at nickel(I) precursors.

The structural, electrochemical, and catalytic properties of a family of iron-containing homogeneous water oxidation catalysts with pendant heteroatoms are studied. Slightly faster O₂ evolution relative to a parent compound is observed when the solvent pH is matched to the pK_a of the pendant nitrogen base, which might be attributable to interactions with substrate water.

Direct metalation reactions of diphenylamine and carbazole were achieved by using amido-bridged dinuclear Al₂ complexes. By comparing the inertness of the aryloxido-bridged dinuclear aluminum complexes for the C–H metalation reaction, we found that the Al₂N₂ core created enough space for the secondary amine substrates to approach the Al–alkyl moiety due to the flexibility of the bridging amido ligand, which allows the Al₂N₂ core to form both a planar and butterfly shape.

Low-valent, electron-rich U^III complexes have the ability to access a wide range of novel reactivity patterns with small molecules. This microreview focuses on the activation chemistry of trivalent uranium complexes towards the industrially relevant small molecules N₂, NO, N₃^–, CO and CO₂, outlining the often unexpected chemistry observed for these reactive U^III centres.

Use of pinacolborane to borylate a hafnocene complex with a highly activated, side-on bound dinitrogen ligand resulted in N–B and M–H bond formation. Carbonylation of the functionalized hafnocene product triggers N–N cleavage to borylimido and formamidido ligands, thereby expanding the scope of CO-induced N₂ bond cleavage.

Electron-rich Ir^I aryl amido complexes undergo heterolytic bond cleavage and one-electron reduction to effect coupling of a coordinated acetonitrile ligand. The dimeric product features a bridging diiminato ligand. The ability to mediate this coupling with a late transition metal attests to the highly donating nature of the PCP pincer ligand environment.

A half-sandwich, 16-electron iron complex with a cyclometalated N-heterocyclic carbene ligand was found to activate the Si–H bonds of hydrosilanes, thus giving rise to coordinatively unsaturated iron–silyl complexes. The silyl complexes interact with H₂ to form 18-electron dihydride complexes.

Three phosphanylbipyridine ligands that react with Cu^I to form dimeric complexes have been synthesized and structurally characterized. The Cu–Cu distance can be controlled by ligand substitution, and electrochemical studies of the dimers suggest that four sequential 1e^– reductions of the bipyridine ligands occur. Catalytic behavior is observed under CO₂.