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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Organometallics 1 (1982), S. 756-757 
    ISSN: 1520-6041
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 3224-3242 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chiral SFeCoM Clusters: Synthesis, Side Reactions, and Proof of ChiralityFrom SFeCo2(CO)9 (1) via the intermediates SFeCo2(CO)8—AsMe2—MCp(CO)3 (3, M = Cr, Mo, W) by the Co—As elimination method the chiral clusters SFeCoMCp(CO)8 (8, M = Cr, Mo, W) could be obtained. From such reactions other clusters resulted too, of which one with a SCo2Mo(μ-AsMe2) framework (10b) and one with a SCo2W(μ-AsCoAs) framework (12) were identified by crystal structure analyses. The chirality of the intermediates 3 as well as that of PMe2Ph derivatives of the clusters 1, 8, and 10 could be proved NMR-spectroscopically by the diastereotopism of the AsMe2- and PMe2 methyl groups, respectively.
    Notes: Aus SFeCo2(CO)9 (1) ließen sich über die Zwischenstufen SFeCo2(CO)8—AsMe2—MCp(CO)3 (3, M = Cr, Mo, W) nach der Co—As-Eliminierungsmethode die chiralen Cluster SFeCoMCp(CO)8 (8, M = Cr, Mo, W) gewinnen. Bei solchen Reaktionen entstanden auch andere Cluster, von denen einer mit SCo2Mo(μ-AsMe2)-Gerüst (10b) und einer mit SCo2W(μ-AsCoAs)-Gerüst (12) durch Kristallstrukturanalyse identifiziert wurden. Sowohl in den Zwischenstufen 3 als auch in PMe2Ph-Derivaten der Cluster 1, 8 und 10 ließ sich die Chiralität NMR-spektroskopisch über die Diastereotopie der AsMe2-bzw. PMe2-Methylgruppen nachweisen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 3243-3256 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chiral SFeCoM Clusters: Enantiomer Separation and Determination of the Absolute ConfigurationThe racemates of the clusters SFeCoMCp(CO)8 (1, M = Cr, Mo, W) were converted by the optically active ligand (—)-(R)-PMePrPh (2) to the pairs of diastereomers SFeCoMCp(CO)7—PMePrPh (3, M = Cr, Mo, W). These could be separated by fractional crystallization. Their reconversion to the pure optically active clusters 1 was achieved by scavenging of the phosphane ligand by methyl iodide under CO pressure. The clusters show rather high [α]-values. The absolute configuration of the molybdenum and tungsten compounds was determined by X-ray analysis and correlation of the ORD spectra. The enantiomers are relatively stable against thermal, but not against photochemical racemization.
    Notes: Die Racemate der Cluster SFeCoMCp(CO)8 (1, M = Cr, Mo, W) wurden mit dem optisch aktiven Liganden (—)-(R)-PMePrPh (2) in die Diastereomerenpaare SFeCoMCp(CO)7—PMePrPh (3, M = Cr, Mo, W) übergeführt. Diese ließen sich durch fraktionierende Kristallisation trennen. Ihre Rückumwandlung in die reinen optisch aktiven Cluster 1 gelang durch Abfangen des Phosphan-Liganden mit Methyliodid unter CO-Druck. Die Cluster zeigen z. T. sehr hohe [α]-Werte. Die absolute Konfiguration der Molybdän- und Wolframverbindungen wurde durch Röntgenstrukturanalyse und Korrelation der ORD-Spektren bestimmt. Die Enantiomeren sind recht stabil gegen thermische, nicht jedoch gegen photochemische Racemisierung.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2438-2451 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Basic Cluster Reactions: Opening and Partial Fragmentation of Tetranuclear Clusters by COThe influence of CO on 16 mixed tetranuclear clusters of the general type M4(μ3-E(μ2-AsMe2) with M = Co, Fe, Ru, Mo, W, and E = S, PR, CR is reported. In all cases fragmentation with formation of trinuclear clusters occurs at slightly elevated pressures, during which a Co - As unit is normally eliminated. At normal pressure intermediates are observed in 7 cases, 4 of which can be isolated. Crystal structure analysis of the intermediate FeCo2MoSAsMe2Cp(CO)10 (8a) has shown that two metal-metal bonds are opened upon addition of CO with formation of the new EM3(μ-AsM) cluster framework. Under vacuum the intermediates are reconverted to the starting clusters with elimination of CO.
    Notes: Bei der Einwirkung von CO auf 16 Hetero-Vierkerncluster des allgemeinen Typs M4(μ3-E)(μ2-AsMe2) mit M = Co, Fe, Ru, Mo, W und E = S, PR, CR tritt in allen Fällen unter geringem Überdruck Abbau zu Dreikernclustern ein, wobei in der Regel eine Co - As-Einheit abgespalten wird. Bei Normaldruck werden in 7 Fällen Zwischenstufen beobachtet, die in 4 Fällen auch isolierbar sind. Durch Kristallstrukturanalyse der Zwischenstufe FeCo2MoSAsMe2Cpt(CO)10 (8a) wird belegt, daß durch Addition von CO zwei Metall-Metall-Bindungen geöffnet werden, wodurch das neuartige EM3(μ-AsM)-Clustergerüst entsteht. Im Vakuum wandeln sich die Zwischenstufen unter Abspaltung von CO wieder in die Ausgangscluster zurück.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2429-2437 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Double Metal Exchange in the Clusters SFeCo2(CO)9 and SRuCo2(CO)9Single metal exchange in SFeCo2(CO)9 (1) and SRuCo2(CO)9 (2) had yielded the mixed metal clusters SFeCoMCp(CO)8 (3, M = Cr, Mo, W) and SRuCoMCp(CO)8 (4, M = Mo, W). For the iron containing clusters 3 the metal exchange by the Co-As elimination method could be applied once more: via the intermediates SFeCoMCp(CO)7 - AsMe2 - M′Ln (5 - 7, M′ = Cr, Mo, W, Mn, Fe) the clusters SFeMM′Cp2(CO)7 (10) were formed, however only for M, M′ = Mo, W. The ruthenium containing clusters 4 reacted by the direct method with [M′Cp(CO)3]2 (M = Mo, W) to form the clusters SRuMM′Cp2(CO)7 (11, M, M′ = Mo, W).
    Notes: Einfacher Metallaustausch hatte aus SFeCo2(CO)9 (1) und SRuCo2(CO)9 (2) die Hetero-Cluster SFeCoMCp(CO)8 (3, M = Cr, Mo, W) und SRuCoMCp(CO)8 (4, M = Mo, W) ergeben. Auf die eisenhaltigen Cluster 3 ließ sich der Metallaustausch nach der Co-As-Eliminierungs-Methode erneut anwenden: über die Zwischenstufen SFeCoMCp(CO)7 - AsMe2 - M′Ln (5 - 7, M′ = Cr, Mo, W, Mn, Fe) entstanden, allerdings nur für M, M′ = Mo, W, die Cluster SFeMM′Cp2(CO)7 (10). Die rutheniumhaltigen Cluster 4 reagierten nach der Direktmethode mit [M′Cp(CO)3]2 (M′ = Mo, W) zu den Clustern SRuMM′Cp2(CO)7 (11, M, M′ = Mo, W).
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 3774-3793 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cluster Construction: Synthesis of Tetranuclear Clusters via AggregationTrinuclear clusters with EM3 frameworks (1-3, EM3 = SFeCo2, SRuCo2, PFeCo2, CCo3) can be connected via CO substitution with AsM′ units (M′ = Cr, Mo, W). The EM3-AsM′ intermediates 7-10 eliminate CO under appropriate conditions to form clusters 13-16 with tetrahedral M3M′ frameworks which bear ų3-E and ų2-AsMe2 ligands. The combinations M3M′ = FeCo2Mo, FeCo2W, RuCo2Mo, RuCo2W, Co3Mo, and Co3W were realized. Starting from trinuclear clusters 4, 5 with the chiral frameworks EM3 = SFeCoMo, SFeCoW, SRuCoMo, and SRuCoW by the same procedure via 11, 12 tetranuclear clusters 17, 18 with the frameworks M3M′ = FeCoMo2, FeCoW2, FeCoMoW, RuCoMo2, RuCoW2, and RuCoMoW are obtained. Among these are the first two clusters with four different metal atoms. The crystal structures of FeCo2MoS(AsMe2)Cp(CO)8 (13a), RuCo2MoS(AsMe2)Cp(CO)8 (14a), and FeCoMoWS-(AsMe2)Cp2(CO)7 (17b) were determined. The tetranuclear clusters show ligand fluxionality as shown by dynamic 1H NMR spectroscopy.
    Notes: An Dreikerncluster mit EM3-Gerüst (1-3, EM3 = SFeCo2, SRuCo2, PFeCo2, CCo3) lassen sich durch CO-Substitution AsM′-Einheiten (M′ = Cr, Mo, W) anbinden. Die EM3-AsM′-Zwischenstufen 7-10 spalten unter geeigneten Bedingungen CO ab, wobei Cluster 13-16 mit tetraedrischem M3M′-Gerüst entstehen, welches ų3-E- und ų-AsMe2-Liganden trägt. Es wurden die Kombinationen M3M′ = FeCo2Mo, FeCo2W, RuCo2Mo, RuCo2W, Co3Mo und Co3W verwirklicht. Ausgehend von Dreikernclustern 4, 5 mit den chiralen Gerüsten EM3 = SFeCoMo, SFeCoW, SRuCoMo und SRuCoW entstehen auf die gleiche Weise über 11, 12 Vierkerncluster 17, 18 mit den Gerüsten M3M′ = FeCoMo2, FeCoW2, FeCoMoW, RuCoMo2, RuCoW2, und RuCoMoW. Unter diesen sind die beiden ersten Cluster mit vier verschiedenen Metallatomen. Von FeCo2MoS(AsMe2)Cp(CO)8 (13a), RuCo2MoS(AsMe2)Cp(CO)8 (14a) und FeCoMoWS-(AsMe2)Cp2(CO)7 (17b) wurden die Kristallstrukturen bestimmt. Die Vierkerncluster zeigen eine Ligandenfluktuation, die durch dynamische 1H-NMR-Spektroskopie zu erfassen ist.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 8
    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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  • 9
    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: 2 Ill.
    Type of Medium: Electronic Resource
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