Untersuchungen zur Existenz der Radikale Cp(CO)₃M (M = Cr, Mo, W) / Investigations on the Existence of the Radicals Cp(CO)₃M (M = Cr, Mo, W)

Abstract

Abstract The mutual interconversions of the species Cp(CO) 3 M - (2), Cp(CO) 3 M-M′(CO) 3 Cp (1), and Cp(CO) 3 M (3), (M,M′ = Cr, Mo, W) were investigated. Of the mixed dinuclear complexes 1, the Cr-Mo and Cr-W compounds were prepared for the first time, and the Mo-W compound was shown not to exist in a pure state. The Mo and W radicals 3, in contrast to the corresponding Cr radical, are not stable in measurable quantities in solution. Electrochemical measurements as well as simple redox and redistribution reactions, however, prove their ready formation and existence under normal conditions. There is a good correlation between the energies of the σ-σ* transitions of the metal-metal bonded dimers (1) and the electrochemical potentials for their reductive cleavage.