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  • 1990-1994  (394)
  • 1980-1984  (343)
  • 1850-1859
  • Inorganic Chemistry  (737)
  • 1
    Electronic Resource
    Electronic Resource
    1,3,4-Oxa- und 1,3,4-Thia-diphospholane aus Diphosphorsubstituierten 2-Oxa- und 2-Thia-propanen (1990)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 589 (1990), S. 187-198 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,3,4-Oxadiphospholanes and 1,3,4-Thiadiphospholanes from Diphosphorus-substituted 2-Oxa- and 2-Thia-propanesThe synthesis of phosphonates and phosphinates of the type (RO)2(O)PCH2ZCH2P(O)(OR)2, R1(RO)(O)PCH2ZCH2P(O)(OR)2 and R1(RO)(O)PCH2ZCH2P(O)(OR)R1 (with Z = O, S; R = Et, Pri; R1 = Me, Ph) is reported. Acyclic diphosphanes, R1(H)PCH2ZCH2P(H)R2 (with Z = O, S; R1 = R2 = H, Me, Ph; R1 = H, R2 = Me), and 1,3,4-Oxadiphospholanes as well as 1,3,4-Thiadiphospholanes are obtained from the esters by reduction.
    Notes: Die Darstellung von Phosphonaten und Phosphinaten der Zusammensetzung (RO)2(O)PCH2ZCH2P(O)(OR)2, R1(RO)(O)PCH2ZCH2P(O)(OR)2, und R1(RO)(O)PCH2ZCH2P(O)(OR)R1 (mit Z = O, S; R = Et, Pri; R1 = Me, Ph) wird beschrieben. Durch Reduktion der Ester sind die acyclischen Diphosphane, R1(H)PCH2ZCH2P(H)R2 (mit Z = O, S; R1 = R2 = H, Me, Ph; R1 = H, R2 = Me) und 1,3,4-Oxadiphospholane bzw. 1,3,4-Thiadiphospholane zugänglich.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19905890120
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of Dehydration of Calcium Hydroxylapatite on its Cell Parameters (1980)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 466 (1980), S. 76-80 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Einfluß der Dehydratation von Calciumhydroxylapatit auf seine ZellparameterHydroxylapatit-Proben mit unterschiedlichem Ca/P-Verhältnissen wurden durch Festkörperreaktion dargestellt.Temperung bei unterschiedlichen Temperaturen bei einem PH2O von 5 mm Hg ergab unterschiedliche Dehydratationsgrade. Die Zellparameter a und c wurden mit hoher Genauigkeit bestimmt und scheinen mit dem OH-Gehalt zu sinken. Die Proben waren bei Raumtemperatur stabil, was die Theorie widerlegt, daß der kariessenkende Effekt des Fluorids auf der Diffusionshemmung im Hydroxylapatit beruht.
    Notes: Hydroxylapatite samples with different Ca/P ratio's were prepared by solid state reaction. Heating at different temperatures under PH2O = 5 mm Hg resulted in different degrees of dehydration. Cell parameters a and c were determined with a high accuracy and appeared to decrease with the OH content. The samples were stable in air at room temperature which disproves the theory that the caries reducing effect of fluoride would be due to the inhibition of diffusion in hydroxyapatite.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19804660109
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  • 3
    Electronic Resource
    Electronic Resource
    Poly- und spirocyclische Silylhydrazone - Synthese und Molekülstrukturen (1984)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 514 (1984), S. 49-60 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Poly- and Spirocyclic Silylhydrazones  -  Synthesis and Molecular StructuresBulky aminotrifluorosilanes react with lithiated dimethylketone-hydrazone to give 1,2-diaza-3-sila-5-cyclopentenes  -  DSCP  -  (1, 2). The 4-silylated (3-5, 8-15) and siloxysilyl-substituted (17, 18) rings eliminate no halosilane or siloxane thermally. Lithiated 2 dimerises with LiF elimination to give the (2+2)cycloadduct of a 1,2-diaza-3-sila-3,5-cyclopentadiene (6). Lithiated DSCP reacts with MeSiF2N(CMe3)SiMe2CMe3 via a nucleophilic 1,3-methanide ion migration to form LiF and the spirocyclic compound 18. A compound with spirocyclic silicon (21) is formed in the reaction of bis(1,2-diaza-3-sila-5-cyclopenten-4-yl)difluorosilane (19) and the lithium salt of dimethyl-ketone-tert-butylhydrazone. The crystal structures of 6 and 21 are reported.
    Notes: Voluminöse Aminotrifluorsilane reagieren mit lithiiertem Dimethylketon-hydrazon zu 1,2-Diaza-3-sila-5-cyclopentenen  -  DSCP  -  (1, 2). In 4-Stellung silyl- (3-5, 8-15) und siloxysilylsubstituierte (17, 18) Ringe spalten thermisch kein Halogensilan oder Siloxan ab. Lithiiertes 2 dimerisiert unter LiF-Abspaltung zum (2+2)Cycloaddukt eines 1,2-Diaza-3-sila-3,5-cyclopentadiens (6). Lithiiertes DSCP reagiert mit MeSiF2N(CMe3)SiMe2CMe3 unter LiF-Ab-spaltung und nucleophiler 1,3-Methanidionen-Wanderung zum Spirocyclus 18. Eine Verbindung mit spirocyclischem Silicium (21) entsteht in der Reaktion des Bis-(1,2-diaza-3-sila-5-cyclopenten-4-yl)-difluorsilans (19) mit dem Lithiumsalz des Dimethylketon-tert-butyl-hydrazon. Die Kristallstrukturen von 6 und 21 werden mitgeteilt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19845140706
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  • 4
    Electronic Resource
    Electronic Resource
    A Fourier Transform Ion Cyclotron Resonance Study of the Structure of some Phenyl-substituted 2-Azaallenium Ions (1983)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 3877-3883 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Eine Fourier-Transform-Ionen-Cyclotron-Resonanz-Studie zur Struktur von Phenyl-substituierten 2-Azaallenium-IonenDurch Protonenabstraktionsreaktionen in Kombination mit Deuterium-Markierungsexperimenten wird gezeigt, daß die Ionen 1-3, die durch Elektronenstoß aus Benzylidenaminen durch Alkylradikal-Abspaltung aus der α-Position erzeugt werden, die Struktur von Phenyl-substituierten 2-Azaallenium-Ionen besitzen. Die durch die Deprotonierung entstehenden Moleküle zeigen sehr hohe Gasphasenbasizitäten (größer als 231.7 kcal/mol).
    Notes: It is shown by proton abstraction reactions in combination with deuterium labelling that the initial structure of the ions 1-3 generated by electron impact from some benzylideneamines through loss of an alkyl radical via α-cleavage is indeed that of phenyl-substituted 2-azaallenium ions. The deprotonated species appear to have very high gas-phase basicities, that are higher than 231.7 kcal/mol.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19831161211
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  • 5
    Electronic Resource
    Electronic Resource
    Synthesis of α,β-Unsaturated and Other Reactive Acyl Cyanides (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 3880-3885 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesen von α,β-ungesättigten und anderen reaktiven AcylcyanidenReaktive aliphatische Acylcyanide (1-10, siehe Tab. 1) werden aus Acylchloriden, Natriumiodid und Kupfer(I)-cyanid unter verschiedenen Bedingungen dargestellt. Die Reaktion verläuft über die Acyliodide.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821151219
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  • 6
    Electronic Resource
    Electronic Resource
    A new approach to dehydrocamphenilone and camphenilone (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 1256-1258 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Eine neue Darstellung von Dehydrocamphenilon und CamphenilonBenzilsäureumlagerung von Dehydrocarbocamphenilon (4) ergibt die α-Hydroxysäure 5, welche mit Bleitetraacetat oxidativ zu Dehydrocamphenilon (2) decarboxyliert wird. Die gleiche Reaktionsfolge führt von Carbocamphenilon (9) zu Camphenilon (3).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150342
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  • 7
    Electronic Resource
    Electronic Resource
    Zweifache Borylierung von Benzolderivaten mit (Diisoalkylamino)boradiyl-Einheiten (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2461-2461 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911241116
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  • 8
    Electronic Resource
    Electronic Resource
    Kooperative Wirkung in π1-Ligand-verbrückten Zweikernkomplexen, XIII. Unerwartet schwache d-d-Wechselwirkungen in synfacialen heterodinuklearen μ1-Cyclooctatetraenkomplexen vom Typ {(CpCr)[(CO)3M′]}μ1-Cot (M′=Fe, Cr, W) (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 553-563 
    Details
    ISSN: 0009-2940
    Keywords: Heterodinuclear cyclooctatetraene complexes ; Paramagnetism ; ESR of electron spin doublet and of electron spin quartet ; Redox properties ; d-d Interactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cooperative Effects in π1-Ligand-Bridged Dinuclear Complexes, XIII[1]. - Unexpected Weak d-d Interactions in Synfacial Heterodinuclear μ1-Cyclooctatetraene Complexes of the Type {(CpCr)[(CO)3M′]}μ1-Cot (M′=Fe, Cr, W)The heterodinuclear complexes {(CpCr)[(CO)3M′]}μ1-Cot (Cot=C8H8; M′=Fe, Cr, W) (5 - 7) and {(Cp*Cr)[(CO)3Cr]}μ1-Cot (Cp*=C5Me5) (9) are synthesized by the reaction of the corresponding mononuclear Cot complexes CpCr(η61-Cot) (4) and Cp*Cr(η61-Cot) (8), respectively, with M′(CO)3(EtCN)3 (M′=Cr, W) and with Fe2(CO)9. The CrFe compound 5 is obtained in very low yield only. However, much better yields of 5 are achieved in the reaction of CrCl2 and CrCp2 with (CO)3Fe(η41-Cot) (10) in the presence of an excess of Zn. X-ray structure determinations of 5 and 6 reveal synfacial configurations of the CpCr and M′(CO)3 units with a μ1-η5:3- and μ1-η4:51-Cot bonding mode for 5 and 6, respectively. The metal - metal distances are 2.9369(13) Å for 5 and 2.81(2) Å for 6 indicating metal - metal single bonds. 5 contains 33 valence electrons (ve) and is paramagnetic with one unpaired electron. A well-resolved fluid-solution ESR spectrum of 5 shows a 53Cr and 1H hyperfine structure (hfs). The 1H hfs can be calculated with three different 1H hyperfine coupling constants (1H hfcc) indicative of protons in α1-position with respect to the paramagnetic metal center: one 1H hfcc of the five Cp protons (1.68 G), one of three (3.32 G) and one of two protons of the Cot ligand (5.04 G). This agrees with the Cot bonding mode of the CpCr unit in the crystalline phase. The ratio of 3:2 protons for the Cot ligand prove the rigidity of the Cot ligand on the ESR time scale. The excellent agreement of the ESR data of the liquid and frozen solution ESR spectra of 5 with the ESR data of the mononuclear complex CpCr(η61-Cot) leads to the conclusion that the unpaired electron in 5 must predominantly be chromium-centered. 6, 7, and 9 have 31 ve and are paramagnetic with three unpaired electrons as shown by means of ESR spectroscopy and magnetic measurements. The calculations of the quartet ESR spectra of 6, 7, and 9 reveal zero-field splitting parameters D ranging from 3.6 to 4.8 cm-1 which are similar to that of the mononuclear quartet compound vanadocene. The small range in the parameters D prove the minor influence of the second metal on going from Cr to W. Hence, the three unpaired electrons are assumed to be mainly localized on the Cr center of the CpCr unit. Cyclic voltammetry studies result in the redoxcascade - 2 ⇄ - 1 ⇄ 0 ⇄ + 1 for 5 and 7 at +20°C and for 6 at -35°C. However, at +20°C 6 and 9 only show one electrochemically reversible reduction wave 0/-1, whereas the oxidation 0/+1 and the second reduction -1/-2 are irreversible. The redox potentials indicate a considerable influence of the metal combinations. On the strength of the ESR spectroscopic results and according to the results of crystal structure determinations, an isolobal relationship is drawn between the (CO)3M′(η8 - ×1-Cot) fragment and a cyclic organic π1-ligand with the hapticity × + 1.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931260302
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  • 9
    Electronic Resource
    Electronic Resource
    Massenspektrometrische Untersuchung von Stickstoff-Verbindungen, XXXV. Phenylsubstituierte 2-Azaallenium-Ionen in der Gasphase (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 2626-2634 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mass Spectrometric Investigation of Nitrogen Compounds, XXXV. Phenyl-substituted 2-Azaallenium Ions in the Gas PhaseThe gas phase chemistry of metastable phenyl-substituted 2-azaallenium ions (2a,b,c) is characterized by intramolecular electrophilic substitution reactions; these processes are energetically favoured in comparison with various phenyl and hydrogen migrations, in spite of the fact that the latter may give rise to the formation of more stable intermediates (nitrilium ions). As a direct consequence of the electrophilic substitution, 2a, c decompose via loss of HCN, whereas from 2b PhCN is eliminated unimolecularly. The combination of experimental investigations, employing [2H]-and [13C]-labelled precursors, and MNDO calculations allows to give a detailed description of the chemistry of isolated 2a,b,c cations.
    Notes: Für die Gasphasenchemie metastabiler phenylsubstituierter 2-Azaallenium-Ionen (2a,b,c) sind intramolekulare elektrophile Substitutionen charakteristisch; diese sind energetisch günstiger als diverse Phenyl- und Wasserstoff-Wanderungen, obwohl letztere zu thermochemisch stabileren Zwischenprodukten (Nitrilium-Ionen) führen. Als Folge der elektrophilen Substitution zerfallen 2a und 2c unimolekular unter HCN-Eliminierung, während aus 2b PhCN eliminiert wird. Experimente unter Benutzung [2H]- und [13C]-markierter Substrate liefern zusammen mit MNDO-Rechnungen ein detailliertes Bild für die Chemie von „isolierten“ 2a,b,c-Kationen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150725
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  • 10
    Electronic Resource
    Electronic Resource
    Anticancer Agents, 17 1,4-Disila[6]radialene: Aktivierungsparameter der Sessel-Twist-Inversion und analytische Enantiomerentrennung der Twist-Konformeren (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2641-2641 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A New Highly Efficient Method for the Synthesis of 1'-Alkyl- and 1'-Phenyl-Substituted Pyrimidine Acyclonucleosides
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911241141
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