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  • 1975-1979  (12)
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 83 (1979), S. 738-741 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 761-768 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of Bis(di-tert-butylmethyl) OxalateThe structure of the title compound (4) has been determined from X-ray data and refined to R = 0.048. 4 crystallizes in the space group C2/c with lattice parameters a = 23.599(4) Å, b = 12827(1) Å, C = 15.272(2) Å and β = 108.89(2)°. - The molecule exhibits the unusual Z-configuration. Bond lenghts and angles show no particularities with the exception of the central C—C-bond which appears significantly short (a = 1.531 Å).
    Notes: Die Struktur der Titelsubstanz (4) wurde röntgenorgraphisch bestimmt und bis zu einem R von 0.048 verfeinert. 4 kristallisiert in der Raumgruppe C2/c mit den Zellparametern a = 23.599(4) Å, b = 12.827 (1) Å, c = 15.272(2) Å und β = 108.89(2)°. - Das Molekül liegt in der ungewöhnlichen Z-Konfiguration vor. Bindungslängen und -winkel zeigen mit Ausnahme der zentralen C—C-Bindung, die mit A = 1.531 Å relativ kurz erscheint, normale Werte.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 1159-1166 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Twisted Oxalic Acid Derivatives The Crystal and Molecular Structure of N,N,N′,N′-Tetramethyloxamide and -monothiooxamideThe structures of the title compounds (2 and 3) have been determined from X-ray data, and refined to R = 0.065 (2) and 0.057 (3) respectively. 2 crystallizes in the space group C2/c, 3 in the space group P21/c. - In the crystal 2 exhibits a configuration in which the two halves of the molecule are twisted by 71.4°. This angle amounts to 87.4° in 3.
    Notes: Die Strukturen der Titelsubstanzen (2 und 3) wurden röntgenographisch bestimmt und bis zu R-Werten von 0.065 (2) bzw. 0.057 (3) verfeinert. 2 kristallisiert in der Raumgruppe C2/c, 3 in der Raumgruppe P21/c. - 2 liegt im Kristall in einer Konfiguration vor, bei der die beiden Molekülhälften um 71.4° gegeneinander verdrillt sind; bei 3 beträgt dieser Winkel 87.4°.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 1511-1517 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkynul Compounds of Transition Metals, XXIX. Alkynyl[ethylenebis(diphenylphosphine)] complexes of Platinum(II)cis-[PtCl2(dpe)] reacts with alkali acetylides in liquid ammonia or liquid methylamine to yield nonionic monomers of the type cis-[Pt(C≡C̊)2(dpe)] (dpe = (C6H5)2P[CH2]2P(C6H5)2; R = H, CH3, C6H5). The analogous reaction with the divalent anion of o-diethynylbenzene, however, gives the polymeric cis-[Pt(C≡C)2C6H4(dpe)]n, cis-[Pt(C≡C)2C6H4(dpe)]n. With an excess of acetylide polymeric complexes of the type [K2Pt(C≡C̊)4(dpe)]n are precipitated.
    Notes: Durch Umsetzung von cis-[PtCl2(dpe)] mit Alkaliacetyliden in flüssigem Ammoniak bzw.flüssigem Methylamin werden nichtionische, einkernige Verbindungen des Typs cis-[Pt(C≡C̊)2(dpe)] (dpe = (C6H5)2P[CH2]2P(C6H5)2; R = H, CH3, C6H5) dargestellt. Eine analoge Reaktion mit dem zweiwertigen Anion des o-Diäthinylbenzols hingegen führt zu einem koordinationspolymeren cis-[Pt(C≡C)2C6H4(dpe)]n. Die Anwendung eines Acetylidüberschusses führt zu polymeren Komplexen des Typs [K2Pt(C≡C̊)4(dpe)]n.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 3792-3798 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of O,O′-Diethyl 5-tert-ButyldithioisophthalateThe structure of the title compound (4) has been determined from X-ray data by means of direct methods and refined to R=0.057. 4 crystallizes in the space group P1¯.  -  The molecule is approximately planar; the interplanar angles between the plane of the benzene ring and those of the RO—CS-groups being 5.3° and 7.6°, respectively. The C=S bond length of 1.631 ± 0.002 Å points to a moderate double bond character.
    Notes: Die Struktur der Titelsubstanz (4) wurde röntgenographisch mit Hilfe der Direktmethode bestimmt und bis zu einem R von 0.057 verfeinert. 4 kristallisiert in der Raumgruppe P1¯.  -  Das Molekül ist fast eben gebaut; die Interplanarwinkel zwischen der Ebene des Benzolrings und denen der RO—CS-Gruppen betragen 5.3° und 7.6°. Die C=S-Bindungslänge von 1.631 ± 0.002 Å läßt auf einen mäßig ausgeprägten Doppelbindungscharakter schließen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 111 (1978), S. 1685-1692 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation, Reactions, Crystal and Molecular Structure of the Cyclic Sulfenylcarboxylate: Methyl 3-Oxo-3H-2.1-benzoxathiole-7-carboxylateOn heating of 2-(benzylsulfinyl)isophthalic acid (4) with acetic acid/acetic anhydride the cyclic sulfenylcarboxylates 7a and 7b are formed in an unexpected elimination reaction and rearrangement, respectively. 7a can be methylated to the title compound 7c. The structure of 7c has been determined from X-ray data and refined to R = 0.06. 7c crystallizes in the monoclinic system, space group P21/c. The molecule is nearly planar and reveals an intramolecular interaction which is reflected in a short S…‥O distance of 252 pm and an unusual IR spectrum (νCO 1750. 1650 cm-1).
    Notes: In einer unerwarteten Eliminierungsreaktion bzw. Umlagerung bilden sich beim Erhitzen von 2-(Benzylsulfinyl)isophthalsäure (4) mit Essigsäure/Essigsäureanhydrid die cyclischen Carbonsäure-Sulfensäureanhydride 7a und 7b. 7a kann zur Titelverbindung 7c methyliert werden. Die Struktur von 7c wurde röntgenographisch bestimmt und bis zu R = 0.06 verfeinert. 7c kristallisiert monoklin in der Raumgruppe P21/c. Das Molekül ist fast planar und zeigt intramolekulare Wechselwirkung, die an einem geringen S…‥O-Abstand (252 pm) und einem ungewöhnlichen IR-Spektrum (νCO 1750, 1650 cm-1) erkannt werden kann.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1975 (1975), S. 1808-1821 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of Thioamides and Their Derivatives, XXXVI. - N-(Trimethylsilyl)thioamides, IThe primary thioamides 1 were treated with hexamethyldisilazane (6) to give N-(trimethyl- silyl)thioamides 3. The strong bathochromic shift of the thioamide B band in the IR spectra of these compounds indicates a weakening of the C—N bond due to dπ - pπ interaction of nitrogen and silicon. The secondary thioamides 7 - 11 were silylated via metallation with potassium or n-butyllithium and reaction with chloro(trimethyl)silane (2). IR- and 1H-NMR spectra indicate an equilibrium between the N-(trimethylsilyl)thioamide 12 and the S-(tri- methylsilyl)-thioimidate 13. With small substituents on the nitrogen and thioacyl carbon of the starting compound only the thioamide structure could be found.  - Free enthalpies of activation were calculated for isomerisation via [1.3-N.S] migration of the trimethylsilyl group and for hindered rotation about the C—N bond.
    Notes: Primäre Thioamide 1 werden mit Hexamethyldisilazan (6) in N-(Trimethylsilyl)thioamide 3 übergeführt. Die starke bathochrome Verschiebung der Thioamid-B-Bande in den IR-Spektren dieser Verbindungen deutet auf eine Schwächung der C—N-Bindung durch dπ - pπ Wechselwirkung zwischen Silizium und Stickstoff hin. Sekundäre Thioamide 7-11 können nach Metallierung mit Kalium oder n-Butyllithium mit Chlorftrimethyl)silan (2) silyliert werden. IR- und 1H-NMR-Spektren weisen auf das Vorliegen eines Gleichgewichtes zwischen N-(Trimethylsilyl)thioamid 12 und S-(Trimethylsilyl)thioimidat 13 hin. Bei sterisch anspruchslosen Substituenten am Stickstoff und am Thioacylkohlenstoff der Ausgangsver- bindung läßt sich jedoch nur die Thioamidform nachweisen. - Freie Aktivierungsenthalpien für die Isomerisierung durch [1.3-N.S]-Wanderung der Trimethylsilylgruppe und für die behinderte Rotation um die C—N-Bindung wurden bestimmt.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of Thioamides and Their Derivatives, XXXII1). - Synthesis, IR- and IH-NMR-spectroscopic Studies on 2-Aminobenzamides and -thiobenzamidesDifferent methods for the synthesis of amides and thioamides of 2-aminobenzoic acid, in particular those in which the protons on both amino-groups are successively exchanged by organic substituents in all possible variations, are reported. From the frequencies and the relative intensities of the NH-stretching vibration bands of these substances in tetrachloro-methane solutions and from the 1H-NMR signal assignments conclusions are drawn regarding the electronic, steric and conformational properties. especially the formation of intramolecular hydrogen bonds of the type NH…X (X = 0, S) and NH…N, as well as the occurrence of E/Z isomerism.
    Notes: Es werden Methoden zur Darstellung von Amiden und Thioamiden der 2-Aminobenzoesäure, und zwar aller durch sukzessiven Austausch der Protonen an beiden Aminogruppen gegen organische Reste denkbaren Varianten, angegeben. Aus der Lage und den relativen Intensitaten der NH-Valenzschwingungsbanden dieser Verbindungen in verdünnten Tetrachlorkohlenstofflösungen und der Zuordnung der 1H-NMR-Signale werden Aussagen über elektronische, sterische und konformative Verhältnisse, insbesondere über die Ausbildung intramolekularer NH … X- (X = 0, S) und NH … N-Wasserstoffbrücken sowie über die E/Z-Isomerie gewonnen.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 89 (1977), S. 743-744 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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