METAL ATOMS IN THE SYNTHESIS OF METAL-CLUSTERS .6. REACTIVITY OF COBALT AND NICKEL ATOMS TOWARDS THE MONONUCLEAR COMPLEXES (ETA(5)-CP(R))CO(CO)2 (R=H, ME4ET, ME5, BU-T(2), PR-I(2) AND (ETA(5)-CP(ME))MN(CO)3 - CRYSTAL-STRUCTURE AND REDOX BEHAVIOR OF [(ETA(6)-MESITYLENE)CO]2CO(ETA(5)-CP(R))(MU(3)-CO)2 (R=ME5, BU-T(2)

The reaction of alkyl-substituted (eta5-Cp(R))(CO)2 complexes with cobalt or nickel atoms in the presence of Cp*H or an arene has been shown to give homo- and heteronuclear M2- and M3-bridged metal carbonyl clusters. The crystal structures of the two homonuclear species obtained in the metal atom reactions, namely [(eta6-mesitylene)Co]2Co(eta5-Cp(R))(mu3-CO)2 with R = Me5 or (t)Bu2, have been determined. The electrochemical behaviour of the clusters [(eta6-mesitylene)Co]2Co(eta5-Cp(R))(mu3-CO)2 (R = Me5, (t)Bu2,(i)Pr2) was studied by cyclic voltammetry and the results are discussed in detail. The reaction of (eta5-Cp(Me))Mn(CO)3 with nickel atoms and Cp*H does not give heteronuclear Mn-Ni cluster compounds, but instead the compound [(eta5-Cp*)Ni]2Ni(eta5-Cp)(mu3-CO)2.