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  • structure elucidation  (6)
  • Polymer and Materials Science  (5)
  • MNDO calculations  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Weak Interactions in Crystals: 4,4′-Di(tert-butyl)-N-N′-bipyridinium Diperchlorate - A Biphenyl Analogue with Perpendicular Pyridine Rings (1995)
    Weinheim : Wiley-Blackwell
    Chemistry - A European Journal 1 (1995), S. 557-563 
    Details
    ISSN: 0947-6539
    Keywords: biphenyls ; bipyridinium salts ; conformation ; semiempirical calculations ; structure elucidation ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oxidation of substituted N-aminopyridinium compounds yields bipyridinium salts. After anion exchange Br- → CIO4-, it was possible to grow single crystals from the 4,4′-di(tert-butyl) derivative. The structure determined at 100 K shows a dihedral angle of 84° between the molecular halves connected by a shortened N—N bond of 143 pm in length. This result is contrary to that expected from the isoelectronic correspondence 〉C—C〈↔〉N—N〈, which would suggest planarity, as has been observed experimentally both in solid biphenyl, and in tetraalkylhydrazine dications and radical cations. Lattice packing analysis, however, reveals the presence of hydrogen bonds C(H)…O between the phenyl rings and the perchlorate anions. AM 1 enthalpy hypersurface calculations for the isoelectronic series H5C5X-YC5H5 (X-Y = C—C, +N—C, +N—N+, -B—N+, B—C, and B—B-) predict single-minimum potentials for both the dication 〉N—N〈 as well as the dianion 〉B—B〈 with the molecular halves twisted perpendicular to each other. In detailed model calculations, counteracting effects of π electron density delocalization vs. H/H repulsion of the ortho ring hydrogens adjacent to the central bond seem to dictate the delicate balance of the biphenyl twisting. For further experimental confirmation, the structure of the isosteric molecule 4,4′-di(tert-butyl)biphenyl has been determined: in contrast to the unsubstituted π hydrocarbon with a latticeenforced dihedral angle of 0°, close to the calculated value, the two molecular halves are twisted by 40° - as in biphenyl in the gas phase.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/chem.19950010810
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  • 2
    Electronic Resource
    Electronic Resource
    Wärmeübertragung an horizontale Einbauten in der Gas/Feststoff-DruckwirbelschichtVortrag von H.-J. Bock auf dem Jahrestreffen der Verfahrens-Ingenieure, 19. bis 21. Sept. 1984 in München. (1985)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 57 (1985), S. 486-487 
    Details
    ISSN: 0009-286X
    Keywords: Druckwirbelschicht ; Wärmeübertragung ; Strömungsmechanik ; Rohrbündel ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330570528
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  • 3
    Electronic Resource
    Electronic Resource
    Einfluß der Strömungsmechanik auf den Wärmeübergang in Gas/Feststoff-WirbelschichtenVorgetragen von H.-J. Bock auf dem Jahrestreffen der Verfahrens-Ingenieure, 26. bis 28. Sept. 1979 in Nürnberg. (1980)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 52 (1980), S. 260-261 
    Details
    ISSN: 0009-286X
    Keywords: Wirbelschicht ; Wärmeübertragung ; Strömungsmechanik ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330520316
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  • 4
    Electronic Resource
    Electronic Resource
    Dimensionierung von senkrechten Wärmeaustauschflächen in Gas/Feststoff-WirbelschichtenVortrag von H.-J. Bock auf dem Jahrestreffen der Verfahrens-Ingenieure, 1.-3. Okt. 1980 in Straßburg. (1981)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 53 (1981), S. 212-213 
    Details
    ISSN: 0009-286X
    Keywords: Wirbelschicht ; Wärmeübertragung ; Strömungsmechanik ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330530318
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  • 5
    Electronic Resource
    Electronic Resource
    Wärmeübertragung in Gas/Feststoff-WirbelschichtenVortrag von H.-J. Bock auf der GVC-Fachausschußsitzung „Mischvorgänge“, 22./23. März 1982 in Bad Dürkheim. (1982)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 54 (1982), S. 838-839 
    Details
    ISSN: 0009-286X
    Keywords: Wirbelschicht ; Wärmeübertragung ; Strömungsmechanik ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330540912
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  • 6
    Electronic Resource
    Electronic Resource
    Strömungsmechanik und Wärmeübergang in einer Wirbelschicht mit grobkörnigen PartikelnVortrag von H.-J. Bock auf dem Jahrestreffen der Verfahrens-Ingenieure, 29. Sept. bis 1. Okt. 1982 in Basel. (1983)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 55 (1983), S. 224-225 
    Details
    ISSN: 0009-286X
    Keywords: Wirbelschicht ; Wärmeübertragung ; Strömungsmechanik ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330550315
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  • 7
    Electronic Resource
    Electronic Resource
    Strukturen ladungsgestörter oder räumlich überfüllter Moleküle. 15. Tetracyanethen-Natrium-Dimethoxyethan (1992)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 614 (1992), S. 109-114 
    Details
    ISSN: 0044-2313
    Keywords: Tetracyanoethene radical anion salt ; single crystal structure ; MNDO calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structures of Charge-Perturbed or Sterically Overcrowded Molecules. 16. Tetracyanoethylene Sodium DimethoxyethaneThe Single crystal structure of [(NC)2C—C(CN)2⊖·Na⊕(H3CO—CH2CH2—OCH3)]∞ reveals two formula units within the triclinic (P1) unit cell. The tetracyanoethylene radical anions are arranged along parallel double layers, which are shifted relative to each other, and in between which are interspersed the sodium counter cations and their dimethoxyethane ligands. The distances within the double layers amount to 300 pm and the ones between them to 385 pm. The six-fold coordinated Na⊕ centers are surrounded by four radical anions with contact distances Na…N between 250 and 254 pm as well as by a twofold solvent ligand with Na…O of 238 and 241 pm. Due to the electron transfer to the acceptor molecule, its (NC)2C-halves twist by 8° and the bond lengths of the N≡C—C subunits, bent by each 3°, are shortened up to 2 pm. The structural parameters are compared to those of the analogous potassium salt [TCNE⊖K⊕DME], of the dianion , of the sodium salts [(NC)3C⊖Na⊕]∞ as well as [(NC)2C—C(CHCH)2—C(CN)2⊖Na⊕]∞ and, in addition, are discussed based on geometry-optimized MNDO calculations.
    Notes: Die Einkristallstruktur von [(NC)2 C — C(CN)2 ⊖ · Na⊕(H3CO—CH2CH2—OCH3)]∞ belegt zwei Formeleinheiten in der triklinen (P1) Einheitszelle. Die Tetracyanethen-Radikalanionen sind entlang paralleler und gegeneinander versetzter Doppelschichten angeordnet, in denen die Natrium-Gegenionen und deren Dimethoxyethan-Liganden eingelagert sind. Der Abstand innerhalb der Doppelschichten beträgt 300 pm, der zwischen ihnen 385 pm. Die sechsfach koordinierten Na⊕-Zentren werden von vier Radikalanionen mit Kontaktabständen Na…N zwischen 250 pm und 254 pm sowie von einem zweizähnigen Solvensliganden mit Na…O von 238 und 241 pm umgeben. Durch den Elektronentransfer auf das Akzeptormolekül verdrillen sich dessen (NC)2C-Hälften um 8° gegeneinander und die Bindungslängen der um 3° geknickten N≡C—C-Einheiten verkürzen sich um bis zu 2 pm. Die Strukturparameter werden mit denen des analogen K⊕-Salzes w[TCNE⊖K⊕DME], des Dianions , der Natrium-Salze [(NC)3C⊖Na⊕]∞ sowie [(NC)2C—C(CHCH)2 — C(CN)2 ⊖ Na⊕]∞ verglichen und zusätzlich anhand geometrieoptimierter MNDO-Berechnungen diskutiert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19926140819
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  • 8
    Electronic Resource
    Electronic Resource
    Photoelektronen-Spektren und Moleküleigenschaften. 133 [1, 2]. Trifluormethyldisulfan und Derivate F3CSSX (X = CF3, F, Cl, Br) (1992)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 611 (1992), S. 125-133 
    Details
    ISSN: 0044-2313
    Keywords: Trifluoromethyldisulfane and derivatives ; Photoelectron spectra ; MNDO calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Molecular Properties. 133. Trifluoromethyldisulfane and Derivates F3CSSX (X=CF3, F, Cl, Br)The He(I) photoelectron spectra of trifluoromethyldisulfane F3CSSH and its derivatives F3CSSX (X=CF3, F, Cl, Br) are assigned by Koopmans correlations, IEnv = -εjMNDO, with MNDO eigenvalues and by radical cation state comparison. Of special interest are the nSπ/nSπ splittings, which amount to 1.15 eV F3C—SS—F or 0.87 eV in F3—SS—Cl, and the dependance of which on the dihedral angle ω(XS—SX), on the SS bond length and on the acceptor effect of the F3C substituents is discussed.
    Notes: Die He(I)-Photoelektronen-Spektren von Trifluormethyldisulfan F3CSSH und seinen Derivaten F3CSSX (X = CF3, F, Cl, Br) werden durch Koopmans-Korrelationen, IEnv = -εjMNDO, mit MNDO-Eigenwerten und durch Radikalkationzustands-Vergleiche zugeordnet. Von besonderem Interesse sind die nSπ/nSπ- Aufspaltungen, die in F3C—SS—F 1,15 eV oder in F3C—SS—Cl 0,87 eV betragen und die in Abhängigkeit vom Diederwinkel ω(XS—SX), der SS-Bindungslänge und dem Akzeptor-Effekt der F3C-Substituenten diskutiert werden.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19926110521
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  • 9
    Electronic Resource
    Electronic Resource
    Photoelektronen-Spektren und Moleküleigenschaften. 132 [1, 2]. Trifluormethylsulfan und Derivate F3CSX (X = CF3, Cl, Br, I) (1992)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 611 (1992), S. 114-124 
    Details
    ISSN: 0044-2313
    Keywords: Trifluoromethylsulfane and derivatives ; Photoelectron spectra ; MNDO calculations ; Thermal decomposition ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photoelectron Spectra and Molecular Properties. 132. Trifluoromethylsulfane and Derivatives F3CSX (X = CF3, Cl, Br, I)The He(I) photoelectron spectra of trifluoromethylsulfane F3CSH and its derivatives F3CSX (X = CF3, Cl, Br, I) are assigned by Koopmans' correlations, IEnv = -εjMNDO, with MNDO eigenvalues, by radical cation state comparison and based on resolved vibrational fine structures, which can' be discussed by MNDO FORCE calculations. The spin/orbit splitting in F3CSI can be approximated by additional ITEREX-85 calculations. Gasphase thermolysis of the trifluoromethylhalogensulfanes F3CSX at 10-4 mbar yields decomposition temperatures, which decrease from X = Cl to I, and as fragmentation products of presumably radical intermediates, in addition to the respective halogens X2 and F2C=S, also F3CX as well as S2 and CS2 (X =Cl, Br) are PE spectroscopically detected.
    Notes: Die He(I)-Photoelektronen-Spektren von Trifluormethylsulfan F3CSH und seinen Derivaten F3CSX (X = CF3, Cl, Br, I) werden durch Koopmans-Korrelationen, IEnv = -εjMNDO, mit MNDO-Eigenwerten, durch Radikalkationszustands-Vergleiche sowie anhand aufgelöster, mit Hilfe von MNDO FORCE-Berechnungen diskutierbarer Schwingungsfeinstrukturen zugeordnet. Die Spin/Bahn-Aufspaltung in F3CSI läßt sich mit zusätzlichen ITEREX-85-Berechnungen erfassen. Gas-phasen-Thermolysen der Trifluormethylhalogensulfane F3CSX bei 10-4 mbar ergeben von X = Cl zu I absinkende Zersetzungstemperaturen und als Produkte der vermutlich über Radikale verlaufenden Fragmentierungen lassen sich außer dem jeweiligen Halogen X2 und F2C = S auch F3CX sowie S2 und CS2 (X = Cl, Br) PE-spektroskopisch nachweisen.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19926110520
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  • 10
    Electronic Resource
    Electronic Resource
    Strukturen sterisch überfüllter oder ladungsgestörter Moleküle. 9. Tetracyanethen-Kalium-DimethoxyethanProfessor Kurt Dehnicke zum 60. Geburtstage gewidmet (1991)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 595 (1991), S. 275-284 
    Details
    ISSN: 0044-2313
    Keywords: Tetracyano radical anion salt ; single crystal structure ; MNDO calculations ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structures of Sterically Overcrowded or Charge Perturbed Molecules. 9. Tetracyanoethylene Potassium DimethoxyethaneThe single crystal structure of [(NC)2C=C(CN)2 ⊖K⊕(H3CO—CH2CH2—OCH3)] reveals 4 formula units per monoclinic (P21/n) unit cell. The tetracyanoethylene radical anions are stapled within slightly undulated layers exhibiting alternating average intermolecular distances of 315 pm and 360 pm between their central C=C bonds. In- between the closer layers both are interspersed the eight-fold coordinated K⊕ counter cations and the solvating dimethoxyethane molecules with contact distances K⊕…N of 282 to 306 pm and K⊕…O of 279 to 294 pm. The molecular halves of the radical anions (NC)2C=C(CN)2⊖ are twisted by 12° and the C=C, C—C and C≡N bond length amount to 142, 142, and 114 pm, respectively. These structural features are discussed by comparison with those of analogous cyanohydrocarbon salts, with those of the neutral molecule, its largely interaction-free anion and its dianion as well as with results of geometry-optimized MNDO calculations.
    Notes: Die Einkristallstruktur von [(CN)2C=(CN)2 ⊖K⊕(H3CO—CH2CH2—OCH3)] belegt vier Formeleinheiten in der monoklinen (P21/n) Einheitszelle. Die Tetracyanethen-Radikalanionen finden sich in leicht gewellten Schichten gestapelt, welche alternierende mittlere intermolekulare Abstände von 315 pm und 360 pm zwischen den zentralen C=C-Bindungen aufweisen. Zwischen den Schichten mit kürzerem Abstand sind die achtfach koordinierten K⊕-Gegenkationen und die Dimethoxyethan-Solvatmoleküle mit Kontaktabständen K⊕…N zwischen 282 pm und 306 pm sowie K⊕…O zwischen 279 pm und 294 pm eingelagert. Die beiden Molekülhälften der Radikalanionen (NC)2C=C(CN)2⊖ sind um 12° gegeneinander verdrillt und die Bindungslängen C=C, C—C und C≡N betragen 142, 142 und 114 pm. Diese Strukturparameter werden durch Vergleich mit denen ähnlicher Cyankohlenwasserstoff-Salze, denen des Neutralmoleküls und seines weitgehend wechselwirkungsfreien Radikalanions und Dianions sowie anhand der Ergebnisse geometrieoptimierter MNDO-Berechnungen diskutiert.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19915950125
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