Electrochemical, spectroscopic, and theoretical study of trinuclear ruthenacyclopentadienyl clusters: Ru3(.mu.-CO)2(CO)6(RC2R)2.

The redox chem. of triruthenium metallacyclopentadienyl clusters Ru3(CO)8(RC2R)2 (R = Et, Ph) has been investigated by electrochem., spectroscopic, and theor. techniques and compared with that of homologous triiron derivs. The sequence of the electrode processes has been postulated on the basis of the responses of different electrochem. techniques, ESR spectroscopy, and chem. tests. The linear correlations between the formal electrode potentials of these derivs. and the wavenumbers of the visible bands of their electronic spectra have been discussed on the basis of the Fenske-Hall quantum mech. approach carried out on the model compds. M3(CO)8(HC2H)2 (M = Fe, Ru) in the idealized C2v geometry.