Mixed valence η6-arene cobalt(i) and cobalt(ii) compound

Abstract

The first carbonyl free mixed valence cobalt(I)/cobalt(II) compound [2{L₂Co(I)(η⁶-C₇H₈)}]²⁺ [Co(II)₂Cl₆]²⁻ (1) [L = PhC(N^tBu)₂SiCl] was obtained by the reaction of four equivalents of anhydrous CoCl₂ with five equivalents of N-heterocyclic chlorosilylene L. In contrast, the reaction of L with CoBr₂ yielded [L₂CoBr₂] (2). Compound 1 was formed by the cleavage of Co–Cl bonds, the reduction of Co(II) to Co(I) and by the coordination of a toluene molecule. The chlorosilylene (L) functions as a reducing agent as well as a neutral σ-donor ligand. The toluene molecule coordinates to the Co(I) atom in an η⁶-fashion.