VARIABLE-TEMPERATURE PROTON NMR-STUDY AND REDUCTIVELY-INDUCED ISOMERIZATION AND DEGRADATION OF [CPCR(CO)(2)(SPH)](2) - CRYSTAL-STRUCTURE OFCP(2)CO[CPCR(SPH)(3)]

The presence of two major (1A and IC) and one minor (1B) geometrical i somers of the complex [CpCr(CO)(2)(SPh)](2) (1) in CH2Cl2 has been obs erved in variable temperature NMR studies. A reversible one-electron r eduction at -0.56 V, as well as a quasi-reversible reduction, attribut ed to IA and IC, respectively, have been observed in electrochemical s tudies. Bulk chemical reduction of 1 by cobaltocene led to the isolati on of Cp(2)Co[CpCr(CO)(3)] (2) and Cp(2)Co[CpCr(SPh)(3)] (3) in ca. 30 % yields each. The compound 3 has been studied by X-ray diffraction an alysis. Crystal data: black prisms, monoclinic, space group P2(1)/n (# 14), a = 16.225(5) A, b = 10.576(3)A, c = 19.99(1) A, beta = 113.49(4) degrees, Z = 4, V = 3147(5) A(3).