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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2382-2392 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Element-Organic Amine/Imine Compounds, XXV. η2-Coordinated s̰3-PhosphazenesThe interaction of the double ylides RR′N - P(X) = NR (1), R = tBu, R′ = Si(CH3)3; X = S, Se, with (Ph3P)2Pt(C2H4) (2) affords the platinum complexes L2(NR)NRR′ (3) with side-on-coordination of the P = X group. Temperature-dependent 1H NMR studies of 3a give evidence that a low temperature the isomer with pentacoordinated silicon atom is favoured. This result is supported by the X-ray structure analysis of 3a which shows a weak N → Si donor-acceptor bond (2.63 Å). The Si - N bond of 3a is cleaved by methanol with formation of L2(NR)NHR (4a), R = tBu.
    Notes: Die Umsetzung der Doppelylide RR′N - P(X) = NR (1), R = tBu, R′ = Si(CH3)3; X = S, Se, mit (Ph3P)2Pt(C2H4) (2) ergibt die Platin-Komplexe L2(NR)NRR′ (3) mit side-on-Koordination der P = X-Gruppe. Temperaturabhängige 1H-NMR-Untersuchungen weisen darauf hin, daß 3a bei tiefen Temperaturen bevorzugt als Isomeres mit pentakoordiniertem Siliciumatom vorliegt. Dieser Befund wird durch die Kristallstrukturanalyse von 3a, die eine schwache N → Si-Donor-Acceptor-Bindung (2.63 Å) erkennen läßt, gestützt. 3a wird von Methanol an der Si - N-Bindung unter Bildung von L2(NR)NHR (4a), R = tBu, gespalten.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1520-6041
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Inorganic chemistry 20 (1981), S. 914-917 
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1520-6041
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 2076-2124 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Element-Organic Amine/Imine Compounds, XXIII. Rotamers of Aminophosphanes and AminophosphoranesThe diazaphosphasiletidines 3a-h can be synthesized from R2Si(NCR3Li)2 and Cl2PNR1R2 (1) as well as from (2) and MNR1R2 (R = CH3). At ambient temperature they show hindered rotation about the P—NR1R2 bond. 3g is separated as a pair of E/Z-rotamers, whose structure has been elucidated by NMR and X-ray analyses. The kinetically measured P—N rotation barriers (ΔG± ≍ 30 kcal · mol-1) are until now the highest that have been measured. The isomerization of 3g(E) → 3g(Z) (P—N) rotation, P inversion, or both) is a P—N rotation which has been established by the synthesis and the NMR spectroscopically measured rearrangement of (3i) (R = CH3, four isomers). The interaction of 3a-h with sulfur, selenium, and methyl iodide gives 4-6a-h. Below 0°C they all show hindered rotation about the P - NR1R2 bond. 4 and 5 are suitable for the study of the structure dependence of 1H NMR ASIS effects. The oxidation of 3g(E/Z) to the isomers 4g-6g(E/Z) occurs with retention of configuration. These compounds show significant differences with respect to their thermal stability and their reaction with methanol. The comparison of the ΔG± values of the P—N rotation barriers of 3-6 shows that the steric influence of the exo-amino substituents R1 and R2 is most important. The E/Z equilibrium of the unsymmetrically substituted compounds gives evidence that the two ground states of P—;N rotation are mostly influenced sterically, possible also electronically.
    Notes: Die Diazaphosphasiletidine 3a-h lassen sich aus R2Si(NCR3Li)2 und Cl2PNR1R2 (1) sowie aus (2) und MNR1R2 (R = CH3) darstellen. Sie weisen bei Raumtemperatur eine Rotationsbehinderung um die P—NR1R2-Bindung auf; 3g wird als E/Z-Rotamerenpaar getrennt und durch NMR- und Röntgenstrukturanalyse charakterisiert. Seine kinetisch ermittelten P—N-Rotationsbarrieren (ΔG± = ca. 30 kcal · mol-1) sind die bislang höchsten bestimmten Werte. Die Umlagerung von 3g(E) → 3g(Z) (P—N-Rotation, P-Inversion oder beides) ist eine P—N-Rotation, was durch Synthese und NMR-spektroskopische Verfolgung der Umlagerung des Isomerengemisches (3i) (R = CH3, vier Isomere) bewiesen wurde. Die Umsetzung von 3a-h mit Schwefel, Selen und Methyliodid ergibt 4-6a-h, die alle unterhalb 0°C eine Rotationsbehinderung um die P—NR1R2-Bindung aufweisen. 4 und 5 sind für das Studium der Strukturabhängigkeit von 1H-NMR-ASIS-Effekten geeignet. Die unter Konfigurationserhalt ablaufende Oxidation von 3g(E/Z) ergibt die Isomerenpaare 4g-6g(E/Z), die bemerkenswerte Unterschiede in bezug auf ihre Methanolyse- bzw. thermische Stabilität aufweisen. Der Vergleich der ΔG±-Werte für die P—N-Rotationsbarriere bei 3-6 zeigt, daß hier vorrangig der sterische Einfluß der exoständigen Aminosubstituenten R1, R2 verantwortlich ist. Aus den E/Z-Gleichgewichtslagen der unsymmetrisch substituierten Verbindungen erkennt man, daß auch die beiden Grundzustände der P—N-Rotation stark sterisch, möglicherweise aber auch elektronisch beeinflußt sind.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 1178-1193 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Azine Complexes of the (Pentamethylcyclopentadienyl)germanium and -tin CationBecause of their electrophilicity the cationic (h5-pentamethylcyclopentadienyl)germanium and -tin units react with pyridine, pyrazine, and 2,2′-bipyridine to form adducts 2 - 4. X-ray structure studies of the pyridine and bipyridine complexes of the C5Me5Sn+ cation (2b, 4b) show a distortion of h5-bonding towards h2- and h3-structures. The structural consequences of the complexation reaction can be understood in terms of the frontier orbitals of the compounds.
    Notes: Die kationische (h5-Pentamethylcyclopentadienyl)germanium- bzw. -zinn-Einheit reagiert aufgrund ihrer Elektrophilie mit Pyridin, Pyrazin sowie mit 2,2′-Bipyridin unter Bildung von Addukten 2 - 4. Röntgenstrukturanalytische Untersuchungen am Pyridin- sowie am Bipyridinkomplex des C5Me5Sn+ -Kations (2b, 4b) lassen eine Verzerrung der ursprünglichen h5-Bindung in Richtung auf eine h2- bzw. h3-Struktur erkennen. Die Strukturellen Konsequenzen der Komplexbildungsreaktione werden im Rahmen einer Diskussion der Grenzorbitale der Komponenten verständlich.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 110 (1977), S. 3241-3244 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ubiquitous Ammonium Tetrasulfur Pentanitride, NH4[S4N5]NH4[S4N5] is formed by the reaction of S2Cl2, SCl2, SCl4, (ClSN)3 and S4N4 with NH3.
    Notes: NH4[S4N5] bildet sich bei der Umsetzung von S2Cl2, SCl2, SCl4, (ClSN)3 und S4N4 mit NH3.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 1126-1131 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [CS3N2Br]+Br3- - A Bromination Product of S4N4 in Carbon DisulfideS4N4 reacts with bromine in CCl4 at ambient temperature to give exclusively a mixture of S4N3Br (1a) and S4N3Br3 (1b). Additional formation of CS3N2Br2 (2a) and CS3N2Br4 (2b) is observed in CS2. The structure of the latter compound is confirmed by X-ray analysis as a cation which shows an almost flat CS2N2 five-membered ring with an S—Br group bonded exocyclically to the carbon atom. The anion is Br3-.
    Notes: S4N4 und Brom bilden in CCl4 bei Raumtemperatur ausschließlich ein Gemisch aus S4N3Br (1a) und S4N3Br3 (1b). In CS2 entstehen zusätzlich noch die Verbindungen CS3N2Br2 (2a) und CS3N2Br4 (2b). Die Röntgenstrukturanalyse weist letzteres als Kation mit einem fast ebenen CS2N2-Fünfring und einer exocyclisch an das C-Atom gebundenen S—Br-Gruppierung aus. Br3- bildet das Anion.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 1070-1082 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Structure of Carbonyl(1,4-diaza-1,3-diene)(1,3-diene)iron Complexes and its Dependence on the Nature of the Diene LigandCompounds 1, (DAD)(diene)Fe(CO), have square pyramidal structures with either N,N' apical/basal coordination of the DAD ligand, type 1-C1, or with N,N' basal/basal coordination in type 1-Cs (DAD = 1,4-diaza-1,3-diene). Structural type 1-Cs, which previously was supported by spectroscopic evidence only, is confirmed by X-ray analysis of carbonyl(2,3-dimethylbutadiene)-[glyoxal-bis(isopropylimine)]iron (1ky). The preparation of identical compounds of type 1-C1 by different routes, and the synthesis of examples of both structural types (characterized by 1H NMR, IR, UV-Vis spectra) by identical routes, but with dienes of different π-acidity, demonstrate that the nature of the diene ligand alone is determining the structural type formed. Thus, independent of the DAD ligand, photolysis of (DAD)Fe(CO)3 4 with donor dienes (butadiene, 2-methylbutadiene, etc.) always yields type 1-Cs, while with the pronounced acceptor diene diethyl muconate (ν) structural type 1-C1 is formed exclusively.
    Notes: Die Verbindungen (DAD)(dien)Fe(CO) 1 besitzen quadratisch-pyramidale Strukturen, in denen der DAD-Ligand entweder N,N'-apikal/basal, Typ 1-C1, oder N,N'-basal/basal, Typ 1-Cs, koordiniert sein kann (DAD = 1,4-Diaza-1,3-dien). Der bisher nur spektroskopisch wahrscheinlich gemachte Strukturtyp 1-Cs wird durch Röntgenstrukturanalyse von Carbonyl(2,3-dimethylbutadien)[glyoxal-bis(isopropylimin)]eisen (1ky) bestätigt. Die Darstellung identischer Verbindungen vom Typ 1-C1 auf unterschiedlichen Wegen sowie die Synthese von Vertretern beider Strukturtypen (Charakterisierung über 1H-NMR-, IR-, UV-Vis-Spektren) auf identischem Wege, aber mit Dien-Liganden unterschiedlicher π-Acidität, zeigen, daß der Strukturtyp nur von der Art des Dien-Liganden abhängt. So ergibt die Photolyse von (DAD)Fe(CO)3 4, unabhängig vom DAD-Typ, mit Donor-Dienen (Butadien, 2-Methylbutadien etc.) immer den Typ 1-Cs, während mit dem ausgeprägten Akzeptor-Dien Muconsäure-diethylester (ν) stets der Typ 1-C1 entsteht.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 127-135 
    ISSN: 1434-1948
    Keywords: Tungsten ; Ditungsten complexes ; Acetylene complex ; Tritungsten complex ; W-W single bond ; W-W triple bond ; Photochemistry ; C-C bond formations ; Olefins ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [W2(η5-C5H5)2(CO)4(μ-η2:2-C2H2)] (1) and ethylene (A) react when irradiated with UV light at 253 K predominantly to [W2(η5-C5H5)2(CO)3(μ-η1:4-C4H5)(μ-H)] (3A), [W2(η5-C5H5)2(CO)4(μ-η1:3-C4H6)] (4A), and thermolabile [W2(η5-C5H5)2(CO)3(η4-C4H6)] (5A). Similarly, propene (B), 1-butene (C), and (E)-2-butene (D) yield mixtures of [W2(η5-C5H5)2(CO)3(μ-H)(μ-η1:4-1,3-dien-1-yl)] (3B, 3 C, 3D), [W2(η5-C5H5)2(CO)4(μ-η1:3-C4H5R] (4B, 4C), and [W2(η5-C5H5)2(CO)2(μ-η1:2-CO)(η4-1,3-diene) (5B, 5 C, 5D). With B and C also thermolabile [W2(η5-C5H5)2(CO)3(μ-η2:2-C2H2)(η2-C2H3R)] (2B, 2C) are formed. A by-product of the reaction of 1 with D is [W(η5-C5H5)(CO)(H){η4-(E)-C5H7CH3}], which is generated in two diastereomeric forms (6, 6′). In contrast, 1 yields no complexes with (Z)-2-butene (E) which contain ligands formed from coordinated acetylene and the olefin. From the reaction mixture only trinuclear [W3(η5-C5H5)3(CO)5(μ-η1:2-C2H3)] (7) was isolated, an alicyclic complex with a W-W single and a W-W triple bond. The crystal and molecular structures of 5D and 7 were determined by X-ray structure analysis. The constitutions of the other complexes were ascertained by IR and 1H-NMR spectroscopy.
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