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Roland A. Fischer Heinz-Josef Kneuper Wolfgang A. Hermann 《Journal of organometallic chemistry》1987,330(3):365-376
Hydrogenchalcogenido complexes of general composition (η5-C5R5)(CO)3M(EH) (R = H, CH3; M = Cr, Mo, W; E = S, Se) can be obtained by three different routes, sometimes in quite good yields. Thus, the sulfur and selenium derivatives can be synthesized by insertion of the respective elements into the metal-hydrogen bonds of the precursor compounds (η5-C5R5)(CO)3MH. This species also reacts with potassium selenocyanate to yield the hydrogenselenido derivatives (η5-C5R5)(CO)3M(SeH) which can also be obtained by treatment of the methyl complexes (η5-C5R5)(CO)3M(CH3 (M = Mo, W) with HBF4 and Li[SeH]. The corresponding hydrogentellurido compounds are probably formed by these preparative methods but appear to be quickly converted into either the dinuclear tellurium bridge products (μ-Te)[(η5-C5R5)(CO)3M]2 (M = Mo) or into the hydrido complexes (η5-C5R5)(CO)3MH (M= Mo, W) by release of elemental tellurium. 相似文献
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Juozas Kulys Heinz-Josef Deussen Kastis Krikstopaitis Palle Schneider Arturas Ziemys 《Monatshefte für Chemie / Chemical Monthly》2001,38(7):295-304
N-Aryl-N-hydroxy urethanes (AHUs), which are promising N*OH mediators for oxidoreductase catalysis, are electrochemically active redox compounds with a redox potential of 0.35–0.40 V vs. SCE (0.59–0.64 V vs. NHE). Alkyl substituents in the carbamic acid residue have, as expected, only little influence on the redox potential. The highest potential was noticed for N-hydroxy-N-(4-cyanophenyl)-carbamic acid methyl ester. Recombinant Coprinus cinereus peroxidase (rCiP) catalyzes oxidation of the AHUs with apparent bimolecular constants k ox of 2.5ċ104–7.5ċ104 M −1s−1 at pH = 8.5 and 25°C. Structure-function connectivities of the substrates were analysed within the framework of the Marcus cross relationship and by using ab initio quantum chemical calculations. An excellent correlation of the redox potentials and the HOMO energies could be found. However, no correlation of log(k ox) with redox potential and HOMO energy was indicated as predicted by theory. This was explained by specific docking of the substrates in the active center of rCiP. 相似文献
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Heinz-Josef Kneuper Peter H rter Wolfgang A. Herrmann 《Journal of organometallic chemistry》1988,340(3):353-358
A series of compounds of general composition (η5C5Me5)Re(=O)X2 (X = halogen, alkyl, alkoxy) was synthesized with ca. 10% 17O enrichment and subjected to 17O NMR spectroscopy. The chemical shift of the terminal oxo function depends on the σ-donor ability of the ligand X and, to a rough approximation correlates to the electron density at rhenium. These results should serve as a useful means to predict and understand reactivities of this class of compounds. 相似文献
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Wolfgang A. Herrmann Dieter Marz Eberhardt Herdtweck Adolf Schfer Werner Wagner Heinz-Josef Kneuper 《Angewandte Chemie (International ed. in English)》1987,26(5):462-464
Selenium dioxide and osmium tetroxide are effective reagents and catalysts for olefin oxidation, although, owing to their toxicity, reservations remain as to their applicability.[1] We are therefore seeking more easily handled metal oxides that are soluble in organic solvents and that are as effective as osmium tetroxide in carrying out stereospecific cis hydroxylation of olefins. The rhenium(VII ) oxide 1 , which has meanwhile become readily accessible, is a favorable candidate.[2] 相似文献
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