Angewandte Chemie International Edition in English

Cover image for Vol. 27 Issue 11

November 1988

Volume 27, Issue 11

Pages 1417–1592

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 11/1988)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198814171

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      The cover picture shows part of a computer-controlled automatic apparatus used for rapid separations of short-lived atomic nuclei by liquid chromatography. A programmable electronic control-unit (shown in the upper half of the picture) schedules the separation procedure. In the center of the picture the position is shown where the products of nuclear-chemical reactions are deposited and dissolved after transportation by a gas-jet. The solution is continuously fed onto either of the two chromatographic columns contained in the metallic heating blocks shown at the bottom of the picture. The flow of different elution media is controlled by pneumatic valves in the red cylinders. Such set-ups are used in the search for superheavy elements. More about the results of these experiments, about the syntheses of the heaviest chemical elements and about the future trends of such studies is reported by G. Herrmann on page 1417ff. (Photo: A. Zschau, GSI Darmstadt).

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
    1. Synthesis of the Heaviest Chemical Elements—Results and Perspectives (pages 1417–1436)

      Prof. Dr. Günter Herrmann

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198814173

      Elements 107, 108, and 109, the three heaviest artificial elements, were prepared by nuclear fusion in the Darmstadt heavy-ion accelerator UNILAC from the heaviest stable atomic nuclei, lead-208 and bismuth-209, and the neutron-richest stable isotopes of chromium and iron. The yields are extremely low; only three atoms of element 109 have so far been observed. All other transuranium elements are also products of nuclear-chemical syntheses. It has not yet been possible to detect the theoretically predicted “superheavy” elements with atomic numbers around 114 and ca. 184 neutrons: while they should be capable of existing, no route for their preparation has yet been devised.

    2. Donor-Acceptor-Substituted Cyclic π-Electron Systems—Probes for Theories and Building Blocks for New Materials (pages 1437–1455)

      Prof. Dr. Rudolf Gompper and Dr. Hans-Ulrich Wagner

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198814371

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      Aromaticity and antiaromaticity have always been a subject of controversy. The donoracceptor concept has afforded new arguments for the understanding of these terms; donor and acceptor substituents in the same molecule stabilize cyclic compounds with (4n) π-electrons (see 1) and destabilize those with (4n+2) π-electrons (see 2, which does not undergo aromatization). New compounds of this type are of interest, for example, for developments in the area of organic metals and in non-linear optics.

    3. Ketenimine Complexes from Carbene Complexes and Isocyanides: Versatile Building Blocks for Carbocycles and N-Heterocycles [New Synthetic Methods (74)] (pages 1456–1467)

      Prof. Dr. Rudolf Aumann

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198814561

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      Five parameters are available for modifying the reactivity of ketenimine complexes [LnM(R1N[DOUBLE BOND]C[DOUBLE BOND]CHR)]: the metal, its ligands and the three substituents in the N[DOUBLE BOND]C[DOUBLE BOND]C unit. Two examples of the multifarious uses of these complexes are firstly the double C,C bond formation at the carbene carbon of the complex 1 with H2C[DOUBLE BOND]CH[BOND]CH2[BOND]NC to give 2 via insertion, formation of the ketenimine complex, rearrangement and ligand exchange and secondly the “dimerization” to yield complexes of type 3: when R = Ph the latter yield dihydro-naphthalenes 4 on warming.

    4. High-Resolution Solid-State 13C-NMR Spectroscopy of Polymers [New Analytical Methods (37)] (pages 1468–1483)

      Dr. Rüdiger Voelkel

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198814681

      Probing the solid state by means of NMR-spectroscopic studies has been made possible by the combination of dipolar decoupling, cross polarization and rotation of the probe at the “magic angle”. Thus, today problems of conformation, crystal structure, molecular dynamics and molecular miscibility of polymers are also studied in industrial laboratories. High-resolution NMR spectroscopy of solids also of course affords information on the structural elements of the substances studied. The scope of one-dimensional CP/MAS-13C-NMR spectroscopy is demonstrated here by studies on industrially important homo- and copolymers.

    5. Phosphaalkynes—Syntheses, Reactions, Coordination Behavior [New Synthetic Methods (73)] (pages 1484–1508)

      Prof. Dr. Manfred Regitz and Prof. Dr. Paul Binger

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198814841

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      Phosphorus compounds with low coordination numbers have been the subject of considerable interest ever since they were first described. One of the show-piece examples is 1, known as tert-butylphosphaacetylene or 3,3-dimethyl-1-phospha-1-butyne. 1 and its analogs can, for example, be incorporated into heterocycles, used as new complex ligands, or cyclooligomerized by organometallic reagents. As far as their reactivity is concerned, phosphaalkynes have little in common with nitriles, but clearly show themselves to be related to the isoelectronic alkynes.

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
    1. Acid-Catalyzed Alkyne/Alkene Coupling at ReIII Centers (pages 1509–1511)

      Prof. Dr. Wolfgang A. Herrmann, Roland A. Fischer and Dr. Eberhardt Herdtweck

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815091

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      A useful intermediate for organorhenium complexes is the alkyne complex 2, which can be formed from the tetrachloride 1. In the presence of catalytic amounts of HBF42 can undergo reaction with ethene and 2-butene to give the 1,3-diene complexes 3 and 4 respectively. Cl/ligand exchange is observed with 1-butyne and acetonitrile in the presence of equimolar amounts of HBF4, but no C[BOND]C bond formation occurs.

    2. Diastereospecific Gas/Solid Additions with Cholesterol Derivatives (pages 1511–1512)

      Prof. Dr. Gerd Kaupp and Christine Seep

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815111

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      Crystals of cholesterol and some of its esters, e.g. 1, add the reactive gases HBr and Br2 both quantitatively and economically. These reactions, which are very simple to carry out, lead to the kinetically controlled diastereospecific formation of the crystalline adducts, e.g. 2, without intermediate melting.

    3. [Ni94-As)6(PPh3)5Cl3], a Cubic Body-centered Ni9-Cluster (pages 1512–1513)

      Prof. Dr. Dieter Fenske, Dr. Kurt Merzweiler and Dr. Johannes Ohmer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815121

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      A lengthening of the Ni[BOND]Ni bonds (from 251–269 to 277–285 pm) is observed when a Ni atom is incorporated into Ni8 cluster. This is shown by the X-ray structural analysis of 1, which is formed (together with 2, a little nickel and further unidentified complexes) from [NiCl2(PPh3)2] and PhAs(SiMe3)2. In contrast, the bonds to the interstitial Ni atom are considerably shorter: Ni[BOND]Ni(Cl) 245–248, Ni[BOND]Ni(PPh3) 238–242 pm, equation image

      • equation image
    4. Organobimetallic Mg[BOND]Pd Complexes as Intermediates in the Formation of Amorphous MgPdCxHy from Mg(C2H5)2 and [Pd(η3-C3H5)2] (pages 1513–1516)

      Prof. Dr. Borislav Bogdanović, Dr. Sara C. Huckett, Ursula Wilczok and Dr. Anna Rufiǹska

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815131

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      1 and 2 were identified by NMR spectroscopy at low temperature as intermediates in the formation of amorphous MgPdCxHy3 from Mg(C2H5)2 and [Pd(η3-C3H5)2]. The experimentally determined product ratio 3: ethene:propene:ethane = 1:2:1:1 can be explained on the basis of the formation of a further intermediate from 2 and Mg(C2H5)2. 3 is of interest as an organometallic precursor for the deposition of intermetallic compounds from the gas phase.

    5. Host-Guest Bonding of Oxoanions to Guanidinium Anchor Groups (pages 1516–1518)

      Dr. Gerhard Müller, Jürgen Riede and Prof. Dr. Franz Peter Schmidtchen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815161

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      Adaptation of the recognition principle of many biogenic receptors, which make use of the interaction between the guanidinium function of arginyl side chains with carboxylate and phosphate groups of substrates, was used to design and synthesize new host compounds. The bicyclic guanidinium compounds (1, shown schematically) bind p-nitrobenzoate (NMR-titration) and acetate (X-ray structural analysis).

    6. Methoxyallenes as Components in Diels-Alder Reactions with Inverse Electron Demand: Synthesis of 6H-1,2-Oxazines (pages 1518–1519)

      Dipl.-Ing. Reinhold Zimmer and Prof. Dr. Hans-Ulrich Reissig

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815181

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      The cycloadditions of nitrosoalkenes 1 to methoxyallene 2 are examples of the until now unusual Diels-Alder reactions with inverse electron demand involving donor-substituted allenes. The regioselectively formed 1,2-oxazine derivatives 3 and 4 are starting materials for the synthesis of further heterocycles. R = Ph, CO2Et, CF3; R′ = H, CH(OH)Me, C(OH)Me2.

    7. Tetrakis[bis(trimethylsilyl)ethyne]diiron (pages 1519–1521)

      Dipl.-Chem. Hartmut Schäufele, Dr. Hans Pritzkow and Dr. Ulrich Zenneck

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815191

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      The first structurally characterized homoleptic metal-alkyne cluster 3 is formed from bis(trimethylsilyl)ethyne and the complexes 1 and 2, which are obtainable by cocondensation. The yield of 3 with respect to vaporized iron is 30–50%. 3 is diamagnetic, so that in spite of the relatively large iron-iron distance (2.465 Å) the presence of an iron-iron double bond must be assumed.

    8. Partially Reversible Intercalation of Ferrocene in a Zeolite-like Host Lattice Consisting of Fe(CN)6 and Me3Sn Units (pages 1521–1522)

      Dipl.-Chem. Peter Brandt, Dipl.-Chem. Abdul K. Brimah and Prof. Dr. R. Dieter Fischer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815211

      Only simply trituration at room temperature is required to cause the complete intercalation of ferrocene in the new 3D coordiantion polymer 1 [eq. (a)]. About 50% of the ferrocene can be sublimed out of the deep-blue paramagnetic intercalate under high vacuum during three days at 80–160 °C.

      • equation image
    9. Structure of a Chiral Lithium Azaenolate: Monomeric, Intramolecular Chelated Lithio-2-acetylnaphthalene-SAMP-hydrazone (pages 1522–1524)

      Prof. Dr. Dieter Enders, Dipl.-Chem. Gerhard Bachstädter, Dr. Kenneth A. M. Kremer, Michael Marsch, Dr. Klaus Harms and Prof. Dr. Gernot Boche

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815221

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      A more detailed insight into the structure of the 1-azaallyl anion of a SAMP-hydrazone has been made possible by the first X-ray crystallographic study of a chiral monomeric azaenolate. The lithiated 2-acetylnaphthalene-SAMP-hydrazone 1 exists as rubyred crystals; it has an η1-structure with intramolecular methoxychelatization, while the lithium ion is solvated by two THF molecules.

    10. On the Structure of the Cation N2Hmath image with an N[BOND]H ċ N Hydrogen Bond in the Monoammonia Adduct of Ammonium Iodide (pages 1524–1525)

      Prof. Dr. Hans Joachim Berthold, Dr. Wolfgang Preibsch and Dipl.-Chem. Elke Vonholdt

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815241

      In spite of the great importance of the N[BOND]H ċ N hydrogen bridge in chemistry and biochemistry, the solid-state structure of the simplest system containing this bond, [H3N[BOND]H ċ NH3], was previously unknown. Single crystal X-ray diffraction studies on NH4I · NH3 have shown that the interaction NHmath image ċ NH3 leads to the formation of the cation N2Hmath image. The N [BOND] N distance determined by least squares refinement is 269(5) pm, somewhat shorter than the equilibrium distance of 273.1 pm calculated in 1982 by Scheiner and Harding.

    11. Selective Photochemical Dehydrogenation of Saturated Hydrocarbons with Quantum Yields Approaching Unity (pages 1526–1527)

      Roman F. Renneke and Prof. Craig L. Hill

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815261

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      The homogeneous systems [nBu4N]4[W10O32]/strong acid/acetonitrile/alkane is the first polymetallate system which makes possible a photo-redox chemistry—transformation of light into chemical energy—with high quantum yields. Alkanes are selectively photo-dehydrogenated by this system using UV light of low energy (λ > 360 nm); reaction 1 [RIGHTWARDS ARROW] 2 is typical.

    12. Slow Tautomerization in a Rhenium-Oxo-Hydroxide Complex (pages 1527–1529)

      Torsten K. G. Erikson and Prof. James M. Mayer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815271

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      The considerable changes in structure and bonding which accompany proton transfer between the two oxygen atoms in 1 cause the tautomerism 11′ to be a slow process: the approach to equilibrium is first order and has a half-life of 11 h! The most important reason for the high activation barrier for the tautomeric equilibrium is the necessary rearrangement of the acetylene ligands.

    13. Linear Twofold Coordination of Arsenic in [Cp′(CO)2Mn[DOUBLE BOND]As[DOUBLE BOND]Mn(CO)2Cp′] (pages 1529–1530)

      Dipl.-Chem. Albert Strube, Prof. Dr. Gottfried Huttner and Dr. Laszlo Zsolnai

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815291

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      An angle of 176.6° at the As atom is found for 1, and X-ray studies show that the Mn[BOND]As[BOND]Mn unit in 2 is also linear. 1 and 2 are thus the first compounds in which an element of the fifth main group exhibits a linear μ2-coordination; the arrangement of the Mn ligands in 1 is in agreement with the allene-like formulation Mn[DOUBLE BOND]As[DOUBLE BOND]Mn.

    14. A Morphology-Selective Copper Organosol (pages 1530–1533)

      Dr. Andrew C. Curtis, Dr. Daniel G. Duff, Dr. Peter P. Edwards, Dr. David A. Jefferson, Dr. Brian F. G. Johnson, Dr. Angus I. Kirkland and Dr. Andrew S. Wallace

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815301

      Hexagonal colloidal copper particles with a narrow size distribution are formed in the reduction of an acetonitrile solution of Cu(OAc)2·H2O with hydrazine hydrate in the presence of poly(vinyl-2-pyrrolidone). The deep-red sols, which were characterized by electron microscopy, are extremely stable in an inert gas atmosphere. They can be redispersed even after complete drying. An insoluble red film is however formed when the dried sol is heated for 30 minutes; this process probably involves polymer cross-linking.

    15. Generation and Characterization of Sulfurous Acid (H2SO3) and of Its Radical Cation as Stable Species in the Gas Phase (pages 1533–1534)

      Detlev Sülzle, Marjon Verhoeven, Dr. Johan K. Terlouw and Prof. Dr. Helmut Schwarz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815331

      Sulfurous acid (H2SO3) and its radical cation H2SOmath image are stable molecules: this has been shown unambiguously by neutralization-reionization. MS experiments and by ab initio calculations. That these species are non-existent in solution is not due to intrinsic factors, but to the medium. The key experiment, with deuterated starting material and product, is shown below.

      • equation image
    16. The SF5-Unit as Steric Protecting Group; Synthesis and Structure of F5S[BOND]C[TRIPLE BOND]SF3 (pages 1534–1536)

      Dipl.-Chem. Rolf Gerhardt, Thomas Gerlbig, Dr. Jürgen Buschamann, Prof. Dr. Peter Luger and Prof. Dr. Konrad Seppelt

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815341

      A linear S[BOND]C[BOND]S unit has been demonstrated for 1 by X-ray crystallography, while that in 2 is bent. Precursors of 1 contain two SF5 units bound to one C-atom; this causes the rotation about the neighboring C[BOND]C bond, e.g., in 3, to be so strongly hindered that even at temperatures above 25°C two separate conformers can be detected by NMR spectroscopy.

      • equation image
    17. α-Methylene-β-lactone, a Novel Heterocyclic Ring System via Deoxygenation of α-Methylene-β-peroxylactones with Triphenylphosphane (pages 1536–1537)

      Prof. Dr. Waldemar Adam, Dipl.-Chem. Ludwig Hasemann and Frank Prechtl

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815361

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      Astonishingly, the title compounds 3 were previously unknown. The first three compounds of this type have now been obtained from the methacrylic acid derivatives 1 via the peroxylactones 2; this once more demonstrates the suitability of phosphanes for the deoxygenation of cyclic compounds. The high degree of functionality of 3 is of interest.

    18. Synthesis and Molecular Structure of the Diphosphaarsirane [{[(η5-C5Me5)(CO)2Fe]P}2AsC66H2tBu3] (pages 1537–1538)

      Prof. Dr. Lothar Weber, Dipl.-Chem. Dagmar Bungardt, Uwe Sonnenberg and Dr. Roland Boese

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815371

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      The phosphorus- and arsenic-containing small ring compounds 3–5 are formed in the reaction between the bis(trimethylsilyl)phosphido complex 1 and the aryldichloroarsane 2. The X-ray structural analysis of 3 affords the first structural parameters for a diphosphaarsirane derivative; however, the values are by no means exceptional ([Fe] = (C5Me5)(CO)2Fe; Aryl = 2,4,6-tBu3C6H2).

    19. Carbon as Leaving Group—Stereochemistry of nucleophilic Substitution (pages 1538–1540)

      Prof. Dr. Wolfgang Kirmse and Dr. Klaus Zander

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815381

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      The fragmentation of bicyclic molecules such as 1 and 3 (X [DOUBLE BOND] Nmath image, OBs) takes place with predominant but incomplete inversion at the electrofugal carbon atom to give 2 and 4 respectively; these reactions must thus be considered as limiting cases of nucleophilic substitution.

    20. Synthesis and Structue of [cyclo-C3H4[BOND]SO2Ph]2Ti[OCH(CH3)2]2, a C-Titanated “α-Sulfonyl Carbanion” (pages 1540–1542)

      Prof. Dr. Hans-Joachim Gais, Dipl.-Ing. Jürgen Vollhardt, Prof. Dr. Hans J. Lindner and Dr. Helmut Paulus

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815401

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      A four-membered chelate ring (O, S, C, Ti) is present in the structure of crystalline 1; this indicates that the Ti atom is bonded via the “carbanion”-C atom and one O atom of the sulfonyl group to the deprotonated sulfone. According to NMR results, 1 also exists in solution as an organotitanium compound.

    21. Use of the CH Acidity of 2,4,4-Trimethyl-4,5-dihydrooxazole to Synthesize Triauriomethanes and Novel Gold Clusters (pages 1542–1544)

      Dipl.-Chem. Franz Scherbaum, Dipl.-Chem. Brigitte Huber, Dr. Gerhard Müller and Prof. Dr. Hubert Schmidbaur

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815421

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      An Aumath image cluster with an unusual structure, the dication 1, is formed in the polyauration of 2,4,4-trimethyl-4,5-dihydrooxazole. The expected dihydrooxazole with a peraurated 2-methyl group reacts further with excess Ph3PAuCl/CsF under Au1-incorporation to give 1. The highly aurated C atoms are trigonal-bipyramidally coordinated. Since the distance between the two central Au atoms is also short (2.811(1) (Å), all the eight Au atoms are components of a cluster. The counterion [Me3SiF2] was also unexpected.

    22. “Aurophilicity” as a Consequence of Relativistic Effects: The Hexakis(triphenylphosphaneaurio)methane Dication [(Ph3PAu)6C]2⊕ (pages 1544–1546)

      Dipl.-Chem. Franz Scherbaum, Andreas Grohmann, Dipl.-Chem. Brigitte Huber, Prof. Dr. Carl Krüger and Prof. Dr. Hubert Schmidbaur

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815441

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      The class of “porcupine compounds”, includes the title cation 1, whose structure has been determined as the BPh4 salt. The analytically, mass-spectrometrically and crystallographically detected interstitial C atom occupies the crystallographic inversion center in an octahedron composed of gold atoms: the structure is probably stabilized by AuċAu interactions. The periphery of tetraauriomethanes is apparently “aurophile” with respect to further LAu ions, so that the hypervalent complex cation [C(AuL)6]2⊕ is formed spontaneously. The supposedly uncentered octahedral cluster cations formulated previously as (AuL)math image were in fact probably indentical with the C-centered species described here.

    23. Iodine-Induced Stereoselective Carbocyclizations: A New Method for the Synthesis of Cyclohexane and Cyclohexene Derivatives (pages 1546–1547)

      Prof. José Barluenga, Dr. José M. González, Dr. Pedro J. Campos and Prof. Gregorio Asensio

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815461

      The ready availability of the starting materials and the extensive possibilities for functionalizing the products are the distinguishing features of the title reaction 1 [RIGHTWARDS ARROW] 2, which is shown exemplarily in equation (a). Further advantages are good yields, high diastereoselectivity, and the simple purification of the carbocyclic products.

      • equation image
    24. Cyclobis(paraquat-p-phenylene). A Tetracationic Multipurpose Receptor (pages 1547–1550)

      Dr. Barbara Odell, Mark V. Reddington, Alexandra M. Z. Slawin, Dr. Neil Spencer, Dr. J. Fraser Stoddart and Dr. David J. Williams

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815471

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      The salt 1ṁ4PF6·3CH3CN is a new type of host molecule, which shows similarities to zeolites but is constructed from organic and inorganic ions. The macrocyclic tetracation 1 can be prepared in two steps from bipyridine and 1,4-bis(bromomethyl)benzene. Calculations and X-ray crystallography showed the tetracation to have a box-like structure in which the p-phenylene and paraquat units are slightly bent. The PFmath image-salt of 1 is soluble in organic solvents, the Cl salt in water. 1·4PF6 in acetonitrile forms weak inclusion complexes with dimethoxybenzenes, which are stabilized by charge-transfer interactions. Structural studies of the inclusion complexes show that the electron-rich guest molecules are located in the cavities (2); because of the stapling of the alternating tetraction and anion/neutral molecule layers these cavities take the form of channels.

    25. Isostructural, Alternately-Charged Receptor Stacks. The Inclusion Complexes of Hydroquinone and Catechol Dimethyl Ethers with Cyclobis(paraquat-p-phenylene) (pages 1550–1553)

      Peter R. Ashton, Dr. Barbara Odell, Mark V. Reddington, Alexandra M. Z. Slawin, J. Fraser Stoddart and Dr. David J. Williams

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815501

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      The salt 1ṁ4PF6·3CH3CN is a new type of host molecule, which shows similarities to zeolites but is constructed from organic and inorganic ions. The macrocyclic tetracation 1 can be prepared in two steps from bipyridine and 1,4-bis(bromomethyl)benzene. Calculations and X-ray crystallography showed the tetracation to have a box-like structure in which the p-phenylene and paraquat units are slightly bent. The PFmath image-salt of 1 is soluble in organic solvents, the Cl salt in water. 1·4PF6 in acetonitrile forms weak inclusion complexes with dimethoxybenzenes, which are stabilized by charge-transfer interactions. Structural studies of the inclusion complexes show that the electron-rich guest molecules are located in the cavities (2); because of the stapling of the alternating tetraction and anion/neutral molecule layers these cavities take the form of channels.

    26. A Novel Type of Cationic Host Molecules with π-Acceptor Properties (pages 1553–1556)

      Dr. Manfred Bühner, Dr. Wolfram Geuder, Dr. Willi-Kurt Gries, Prof. Dr. Siegfried Hünig, Dipl.-Chem. Michael Koch and Dr. Thomas Poll

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815531

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      Surprisingly, the template effect of a hydrocarbon has been detected for the first time: the yield in the one-pot synthesis of the tetracationic macrocycle 1c is raised from 3–5% to 16% when excess phenanthrene is present. The new phane-like tetracations 1a-c and 2a-c act as π-acceptor host compounds and take up arenes as π-donors in their cavities in a sandwich-like manner.

    27. Gas Chromatographic Separation of Enantiomeric Olefins (pages 1556–1558)

      Dipl.-Chem. Jens Ehlers, Prof. Dr. Wilfried A. König, Dipl.-Chem. Sabine Lutz, Dr. Gerhard Wenz and Prof. Dr. Heindirk tom Dieck

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815561

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      A perpentylated β-cyclodextrin stationary phase permits the unproblematic enantiomer separation of chiral olefins. Even acyclic olefins such as 1, which is formed in the enantioselective reaction between pentadiene and ethene at a chiral iron catalyst, can be separated; this makes possible a simple determination of the enantiomeric yield.

    28. Reaction of Tropone with a Homopyrrole. The Result of a Computer-Assisted Search for Unique Chemical Reactions (pages 1558–1559)

      Dipl.-Chem. Dietmar Forstmeyer, Dr. Johannes Bauer, Dr. Eric Fontain, Dr. Rainer Herges, Dr. Rudolf Herrmann and Prof. Dr. Ivar Ugi

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815581

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      One of the few examples of a [4 + 6]-cycloaddition reaction involving homodienes and trienes is the reaction (a). The isolated product 3 is probably formed in an intramolecular Diels-Alder reaction of the [4+6]-adduct 4. The formation of 4 from 1 and 2 was predicted by the computer program IGOR.

    29. First Structure Analysis and Photoelectron Spectroscopic Investigation of an Azete and an Azete-Cobalt Complex (pages 1559–1562)

      Dipl.-Chem. Martin Ledermann, Prof. Dr. Manfred Regitz, Dr. Klaus Angermund, Prof. Dr. Paul Binger, Prof. Dr. Carl Krüger, Dr. Richard Mynott, Prof. Dr. Rolf Gleiter and Dr. Isabella Hyla-Kryspin

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815591

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      The antiaromatic 2,3-ditert-butyl-4-mesityl axete 1 exists in the crystal only as the valence isomer 1A. The four-membered ring has the structure of a distorted rectangle, and the interplanar angle between the aromatic and antiaromatic rings is 70°. The valence isomer 1B participates to at most 5% in an equilibrium (13C NMR). In contrast, the bond lengths in the four-membered ring are almost equal in the azete-cobalt complex 2 because of electron delocalization.

    30. 4-Iodo-1,3,5,7-tetramethyl-1,3,5,7-tetraaza-4λ5-phosphaspiro[3.3]heptane-2,6-dione: Synthesis and Crystal Structure of the First Iodophosphorane (pages 1562–1563)

      Dr. Johannes Breker, Prof. Dr. Peter G. Jones, Dr. Dietmar Stalke and Prof. Dr. Reinhard Schmutzler

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815621

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      A trigonal-bipyramidally coordinated P atom is the characteristic structural element of the title compound 2, which can be synthesized from the readily available 1 by Cl/I exchange. The crystals of 2 are pale yellow at −30°C, but at room temperature light brown; they decompose above 50°C. The P-I bond, which is without precedent, is 245.8(3) pm long.

    31. Coordination of H2 and O2 to [OsHCl(CO)(PiPr3)2]: A Catalytically Active M(η2-H2) Complex (pages 1563–1564)

      Dr. Miguel A. Esteruelas, Dipl.-Chem. Eduardo Sola, Prof. Dr. Luis A. Oro, Dipl.-Chem. Uwe Meyer and Prof. Dr. Helmut Werner

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815631

      Both H2 and O2 are coordinated to the coordinatively unsaturated comples 1 without bond breaking. While 1·H2 is only stable in a hydrogen atmosphere, 1·O2 does not split off oxygen even under high vacuum. At 60°C in solvents such as benzene, 1,2-dichloroethane and 2-propanol 1·H2 catalyzes the reductions of alkenes and -unsaturated ketones: thus for example benzylidene-acetone in 2-propanol gives benzylacetone and 4-phenyl-2-butanol in a ratio of 54:1.

      • equation image
  3. Book Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
  4. Editorial Essay

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
    1. Materials Federations—The State of Play (pages 1569–1573)

      Prof. Robert W. Cahn

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815691

  5. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
    1. New Donors for Molecular Organic (Super)Conductors and Ferromagnets (pages 1573–1577)

      Prof. Dr. Zen-ichi Yoshida and Dr. Toyonari Sugimoto

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815731

  6. Research News

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
    1. Beryllium Crystals for Neutron Monochromators (page 1578)

      Sibylle Stiltz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815781

  7. Conference Report

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
    1. Liquid Crystals Centenary (pages 1580–1582)

      Horst Stegemeyer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815801

    2. Synthetic Metals—Coming of Age But Still Controversial (pages 1583–1584)

      Jürgen Rühe and Tiberio A. Ezquerra

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815831

    3. Surface and Colloid Science (pages 1584–1585)

      Naoya Ogata

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815841

  8. Conference Calendar

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Editorial Essay
    6. Reviews
    7. Research News
    8. Conference Report
    9. Conference Calendar
    1. Conference Calendar (pages 1586–1592)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198815861

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