Angewandte Chemie International Edition in English

Cover image for Vol. 26 Issue 2

February 1987

Volume 26, Issue 2

Pages 93–160

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 2/1987)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198700931

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      The cover sows an extremely unusual cyclohexane derivative. In this [6.5]coronane, each pair of neighboring C atoms of the six-membered ring are joined by a [BOND](CH2)3[BOND] bridge, resulting in the formation of six-additional rings. The 13C-NMR spectrum of the compound is only in agreement with a rapidly inverting species having an all-cis conformation. Low-temperature spectra, as well as force field calculations, on an analogue containing only five additional rings, indicate that the central ring exists in a flattened chairconformation. Further details are reported by L. Fitjer et. al. on p. 130 ff.

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Difficulties in the Emergence of the Polymer Concept—an Essay (pages 93–97)

      Pof. Herbert Morawetz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198700933

      The emergence of polymer science as a discipline in itself followed a long and tortuous road, pitted with misconceptions. Indeed, in view of the importance today of plastics and man-made fibers, it is hard to imagine these early difficulties. The essay begins with the first true polymer experiments at the beginning of the last century and ends with the establishment of the polymer concept approximately fifty years ago.

    2. Sulfur Oxides as Ligands in Coordination Compounds (pages 98–109)

      Prof. Dr. Wolfdieter A. Schenk

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198700981

      SO2, SO3, SO, S2O, S2O2—all these sulfur oxides are bound by transition metals; in fact, the latter three are only stable in complex-bound form. These examples once again support the rule that, upon binding to a metal, stable species may be activated to undergo novel reactions and unstable species may be stabilized.

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    3. Nuclear Quadrupole Interaction and Time-Resolved Perturbed γ-γ-Angular Correlation Spectroscopy: Applications in Chemistry, Materials Science, and Biophysical Chemistry. New Analytical Methods (31) (pages 110–126)

      Dr. Anton Lerf and Dr. Tilman Butz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701101

      Valuable information concerning charge density distributions is obtainable by the study of nuclear quadrupole interactions. Whereas NMR and Mössbauer spectroscopy have become routine procedures in chemistry, this is not yet the case for time-resolved spectroscopy of the perturbed γ-γ-angular correlation (TDPAC spectroscopy). However, this technique is ideally suited for applications in chemistry (e.g., comparison of the bonding of complexes in the solid state, in solution, or in melts), materials science (e.g., investigations of catalyst surfaces), and molecular biology (e.g., studies of the dynamics of biomolecules).

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Conversion of η4-Bound Cyclopentadiene into the Complexed Carbene Cyclopentadienylidene (pages 127–128)

      Dr. Hubert Wadepohl and Dr. Hans Pritzkow

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701271

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      Should the bridging cyclopcntadienylidene ligand in 1 be regarded as η41(diene/carbene)- or η5, η1(ylide)-coordinated? Crystal structure data favor the diene/carbene structure. The reversal of the Lewis acid-base properties of cyclopentadienylidene upon complexation may be ascribed to blocking of the diene π* orbitals. L = PMe3.

    2. A Biocatalyst for the Preparation of (R) and (S)-2-Hydroxycarboxylic Acids (pages 128–130)

      Dipl.-Chem. Haike Skopan, Dr. Helmut Günther and Prof. Dr. Helmut Simon

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701281

      “Biocatalytic enantiomer resolution of 2-hydroxycarboxylic acids”, rac-1, has been achieved with the (nonisolated) 2-oxoacid reductase from Proteus vulgaris. This enzyme is usually employed to reduce 2-oxomonocarboxylic acids to (R)-2-hydroxycarboxylic acids (> 99% ee) with methyl- or benzylviologen as electron mediator. The use of carbamoylmethylviologen has allowed, for the first time, the reverse reaction to be carried out. Only the (R) enantiomer of rac-1 undergoes dehydrogenation; the (S)-2-hydroxycarboxylic acid remains unchanged. The mediator can be regenerated.

    3. Heptacyclo[,5.05,9.09,13.013,17.017,21]-tetracosane([6.5]coronane) (pages 130–132)

      Dipl.-Chem. Detlef Wehle and Prof. Dr. Lutz Fitjer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701301

      Thumbnail image of graphical abstract

      Radical cyclization of 1 provided the first route to an [m.n]coronane. the title compound 2. The main product, however, is the heptacyclic compound 3. The coronane 2 has an all-cis configuration, exists in the chair conformation, and undergoes inversion extremely rapidly with ΔGmath image ≤ 36 kJ mol−1 (AIBN = azobisisobutyronitrile).

    4. Oxidative Addition of Hydrogen Telluride to Organometallic Fragments (pages 132–134)

      Prof. Dr. Wolfgang A. Herrmann, Dr. Christian Hecht, Dr. Eberhardt Herdtweck and Dr. Heinz-Josef Kneuper

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701321

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      Complex 1 occupies a position of central importance in the preparation of multinuclear organometallic complexes with “naked” tellurium. 1 was obtained from [(C5Mes5)Re(CO)2(thf)] (thf = tetrahydrofuran) in the title reaction. Complex 1 and the compounds obtained from it were characterized by several methods, including 125Te-NMR spectroscopy.

    5. Sulfur Pentafluoride Cyanate, F5S[BOND]O[BOND]C[TRIPLE BOND]N (pages 134–135)

      Dipl.-Chem. Arno Schmuck and Prof. Dr. Konrad Seppelt

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701341

      A new member has been added to the scries of pcntafluorochalcogen cyanates and isocyanates. The title compound 1 was prepared from F5S[BOND]O[BOND]CI and CI2C[DOUBLE BOND]NCI via the adduct F5S[BOND]O[BOND]CCl2[BOND]NCl2, which could be stepwise deculorinated. Heating of compound 1 at high temperatures affords only traces of F5S[BOND]N[DOUBLE BOND]C[DOUBLE BOND]O.

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    6. Heterometallic Polyhydride Raft Formation: A Comparison of Syntheses using Alkoxides of Copper and Gold (pages 135–137)

      Dr. Bruce R. Sutherland, Dr. Douglas M. Ho, Dr. John C. Huffman and Prof. Kenneth G. Caulton

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701351

      Relatively strong Cu–H and Cu–Cu interactions are the main reason that the most hydride-rich cluster so far observed, the neutral cluster 3, is formed upon reaction of the Re2H8 complex 1 with 2. Complex 1 reacts with the gold complex 4, which is analogous to 2, to give the hexahydrido complex 5, for which the formula represents both a symmetrical and an unsymmetrical isomer.

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    7. The Copolymer of 2,6-Pyridinedimethanethiol and 1,4-Benzenedimethanethiol (pages 137–139)

      Dr. Giovanni Modica, Dr. Silvia Maffi, Dr. Enzo Mantoneri, Luigi Giuffré and Dr. Antonio Grassi

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701371

      The first polymer containing pyridinc rings as part of the backbone chain, the title compound 3, was prepared from the two bis(chloromethyl) compounds 1 and 2 and Na2S. 3 is insoluble, but melts (m.p. = 177°C) and can undergo extrusion to produce films. With Na2S alone, 1 forms a cyclic tetramer.

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    8. The Crystal Structure of Mn2O7 (pages 139–140)

      Prof. Dr. Arndt Simon, Richard Dronskowski, Prof. Dr. Bernt Krebs and Bernhard Hettich

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701391

      Mn2O7—a long-known compound, whose crystal structure has finally been elucidated: the Mn atoms are surrounded tetrahedrally by O atoms; the bridging and the terminal Mn–O bonds are, as expected, of different lengths. The Mn2O7 molecules are packed in such a way that an only slightly distorted fcc arrangement results for the O atoms.

    9. CO2 Elimination from Vinylene Carbonate Radical Anions and Charge Reversal in C2H2O⊙⊖: Reactions Involving the Radical Anion and Cation of Oxirene? (pages 140–142)

      Ben L. M. van Baar, Nikolaus Heinrich, Dr. Wolfram Koch, Ron Postma, Dr. Johan K. Terlouw and Prof. Dr. Helmut Schwarz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701401

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      The first oxirene derivative, 3, was one of the products obtained from vinylene carbonate 1 in the gas phase. Electron attachment to 1, followed by elimination of CO2 and subsequent removal of two electrons from the radical anion, leads to the radical cation 2, which, depending on its internal energy, can also undergo isomerization to the stable oxirene radical cation 3, which was predicted by theory to be a stable species.

    10. Stereoselective Alkylation of Aromatic Compounds with Threonine Trifluoromethanesulfonates (pages 142–143)

      Prof. Dr. Franz Effenberger and Dipl.-Chem. Thomas Weber

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701421

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      Complete retention of configuration at C-2 and a surprising degree of retention (> 96% ee) at C-3 was observed upon reaction of the threonine derivatives (2S,3R)- and (2R,3S)-1 with benzene. In the case of the allothrconine derivatives (2S,3S)- and (2R,3R)-1, on the other hand, 2 :3 mixtures of diastereomers result. This is ascribed to hindered rotation in the carbocation that is formed from the threonine derivatives.

    11. Asymmetric Synthesis of Cyclic α-Amino Acids by the Bislactim Ether Method (pages 143–145)

      Prof. Dr. Ulrich Schöllkopf, Dipl.-Chem. Rolf Hinrichs and Dr. Ralph Lonsky

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701431

      Thumbnail image of graphical abstract

      Methylproline, 1a, and its cyclic homologues, 1b and 2, have been synthesized without direct recourse to the “chiral pool.” The multistep synthesis starts from the bislactim ether 3 and the dibromides 4a,b and 5 (a, n = 1; b, n = 2).

    12. [Ag4(SCH2C6H4CH2S)3]2−, a Novel Polynuclear Silver Thiolate with Trigonal-Planar Coordination of All Silver Atoms and a Central [Ag4S6]-Cage (pages 145–146)

      Priv.-Doz. Dr. Gerald Henkel, Dr. Peter Betz and Prof. Dr. Bernt Krebs

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701451

      Thumbnail image of graphical abstract

      The first silver complex containing an [M4S6] structural unit, the anion 1, has now been synthesized; numerous examples of Cu1 complexes containing this structural unit are already known. The [Ag4S6] cage consists—in idealized terms—of an S6 octahedron with an Ag4 tetrahedron, which is so oriented that the octahedral faces are alternately occupied by Ag atoms. In the picture on the right, the Ag atoms are drawn in black.

    13. Unusual Photoisomerization of a Cyclic Sulfonamide (pages 146–147)

      Prof. Dr. Dietrich Döpp, Prof. Dr. Carl Krüger, Dipl.-Chem. Peter Lauterfeld and Dr. Eleonore Raabe

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701461

      Thumbnail image of graphical abstract

      The S[BOND]C, S[BOND]N, and N[BOND]C bonds in the five-membered ring do not undergo cleavage when the sulfonamide 1 is irradiated. Instead, the sulfinehydroxamic acid 2 is formed, which is stable in crystalline form but isomerizes back to 1 in solution. An intermolecular hydrogen bond is of critical importance for the stability of crystalline 2.

    14. Azulene as Unusual η6-Ligand and as η64-Bridge in Mo-Complexes (pages 147–148)

      Dr. Susanne Töfke and Prof. Dr. Ulrich Behrens

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701471

      In the mononuclear complex (azulene)(benzene)molybdenum, 1, the azulene ligand behaves as if it consisted of a fulvene and a diene moiety. This is also true of the binuclear complexes obtained by reaction of 1 with [(H3CCN)3M(CO)3] (M = Cr, Mo, W). In 1, the η6-coordinated azulene is nonplanar; the binuclear complexes exhibit fluxional behavior in solution, which was still observed at 193 K and results in only five signals in the 1H-NMR spectrum.

    15. Novel Ni-Clusters with Se and PR3 (R[DOUBLE BOND]Ph, Et) as Ligands (pages 148–151)

      Prof. Dr. Dieter Fenske and Dipl.-Chem. Johannes Ohmer

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701481

      Parallel planes formed by three Ni and three Se atoms are common features of the complexes 2–4 in the crystal. Complex 1 contains a trigonal Ni6 prism with Se atoms lying above each face. Complexes 2–4 consist of face-sharing Ni6 octahedra with the Se atoms as μ3 and μ4 ligands.

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    16. Chromatographic Separation of Higher Polythionates SnOmath image (n = 3…22) and Their Detection in Cultures of Thiobacillus ferroxidans; Molecular Composition of Bacterial Sulfur Secretions (pages 151–153)

      Prof. Dr. Ralf Steudel, Gabriele Holdt, Dipl.-Chem. Thomas Göbel and Ir. Willem Hazeu

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701511

      Polythionate ions containing up to 22 sulfur atoms have been separated by ion-pair chromatography. The ions are formed in mixtures of thiosulfate and chlorosulfanes and upon oxidation of tetra- or pentathionate with Thiobacillus ferrooxidans. The sulfur globules formed as intermediates were also investigated. Their core consists mainly of S8 with polythionate ions on the hydrophilic surface. The eluent consisted of a mixture of acetonitrile and water with a linearly decreasing concentration of (NBu4)H2PO4 and Na2CO3.

    17. CC-Linkages of Ethene with CO2 on an Iron(0) Complex—Synthesis and Crystal Structure Analysis of [(PEt3)2Fe(C2H4)2] (pages 153–155)

      Prof. Dr. Heinz Hoberg, Dipl.-Chem. Klaus Jenni, Dr. Klaus Angermund and Prof. Dr. Carl Krüger

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701531

      The first metal-induced syntheses of dicarboxylic acids from ethylene and the C1 building block CO2 have been achieved by use of the title compound 2, an unsaturated 16-electron Fe0 system. By addition of ligands, the reactions can be controlled to give either the methylmalonic acids 1 or the isomeric succinic acids 3 preferentially.

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    18. Isolation and Photoisomerization of Simply Substituted Nitrile Oxides (pages 155–156)

      Prof. Dr. Günther Maier and Dipl.-Chem. Joaquim Henrique Teles

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701551

      Simple derivatives of fulminic acid, such as 1a–c, can be isolated in an argon matrix, identified spectroscopically, and transformed photochemically into the isocyanates 2a–c. The educts 1 are formed by gas-phase pyrolysis of the corresponding hydroxmoyl halides X(Hal)C[DOUBLE BOND]N[BOND]OH.

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    19. 2H,2H-COSY and 2H,2H,13C-RELAY NMR Experiments for the Analysis of Deuteriated Compounds (pages 156–157)

      Dipl.-Chem. Detlef Moskau and Prof. Dr. Harald Günther

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701561

      Determination of the homonuclear coupling between and the correlation of 13C nuclei via vicinal deuterium nuclei has been achieved by 2D NMR spectroscopy. [D5]Pyridine was used to show that the only 0.1- to 0.2-Hz 3J(2H,2H) values lead to significant cross signals in the COSY experiment and that the RELAY experiment is a promising alternative when 2H,13C correlation and 2H,2H COSY NMR spectroscopy fail owing to overlapping of signals.

  3. Book Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Book Review: Geschichte de Elektrochemie. By L. Dunch (page 160)

      Wolgang Schmickler

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198701601