Electrochemical, Spectroscopic, and Theoretical Study of Trinuclear Ruthenacyclopentadienyl Clusters Ru3(μ-CO)2(CO)6(RC2R)2

The redox chemistry of triruthenium metallacyclopentadienyl clusters Ru3(CO)8(RC2R)2 has been investigated by electrochemical, spectroscopic, and theoretical techniques and compared with that of homologous triiron derivatives. The sequence of the electrode processes has been postulated on the basis of the responses of different electrochemical techniques, electron spin resonance (ESR) spectroscopy, and chemical tests. The linear correlations between the formal electrode potentials of these derivatives and the wavenumbers of the visible bands of their electronic spectra have been discussed on the basis of Fenske-Hall quantum mechanical approach carried out on the model compounds M3(CO)8(HC2H)2 (M = Fe, Ru) in the idealized C2v geometry.