ansa -Chromocene Complexes. 1. Synthesis and Characterization of Cr(II) Carbonyl and tert -Butyl Isocyanide Complexes
2000; American Chemical Society; Volume: 19; Issue: 8 Linguagem: Inglês
10.1021/om9909993
ISSN1520-6041
AutoresGilbert J. Matare, David Min Jin Foo, Kevin M. Kane, Ralph A. Zehnder, Marion Wagener, Pamela J. Shapiro, T. Concolino, Arnold L. Rheingold,
Tópico(s)Metal complexes synthesis and properties
Resumoansa-Calcocene compounds are effective reagents for the synthesis of ansa-chromocene complexes from CrCl2 in the presence of a trapping ligand such as carbon monoxide or an isonitrile. A variety of ansa-chromocene carbonyl and tert-butyl isocyanide complexes have been prepared in this manner in high yields. The X-ray crystal structure of one of these complexes, [trans-1,2-(3,4-(CH3O)2C6H3)2C2H2{η5-C5H4}2]CrCO, is described. Electrochemical studies on these complexes show that the isonitrile derivatives are more easily oxidized than the carbonyl derivatives. Preliminary examination of the reactivity of these complexes indicates that the nature of the substitution along the ethanediyl ansa-bridge influences the relative stabilities of the carbonyl complexes to oxidation in air, the ease with which the carbonyl ligands undergo substitution with tert-butyl isocyanide, and the relative sensitivities of the tert-butyl isocyanide adducts to photodecomposition. The ansa-bridge substitution also appears to influence the ability of the complexes to undergo structural changes, such as ring slippage, as revealed in their cyclic voltammograms.
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