COVALENT NATURE OF THE METAL-HALOGEN BONDS IN TRINUCLEAR OSMIUM CARBONYL HALIDES

Comparison of the results of the electrochemical reduction of trinuclear osmium carbonyl halides with linear structure, Os3(CO)12X2, and nonlinear structure, Os3(CO)10(μ-X)2 (X=I, Br, and Cl) with mononuclear carbonyl halides of transition metals indicates covalent nature of the metal-halogen bonds in these compounds. Chemical dissociation does not occur upon dissolving the trinuclear osmium carbonyl halides in acetonitrile and the cleavage of the Os-X bonds is a result of the electrochemical reduction. The observed order for ease of reduction of the trinuclear osmium carbonyl halides coincides with the change in the E1/2 values in the reduction of the mononuclear carbonyl halides of transition metals and alkyl halides. © 1990 Plenum Publishing Corporation.