ELECTRON-TRANSFER BETWEEN MONONUCLEAR METAL-CARBONYL ANIONS (M(CO)5-,M=MN,RE, CPFE(CO)2-, CPM(CO)3-,M=CR,MO) AND TRINUCLEAR CLUSTERS (M3(CO)12,M=FE,RU,OS) AND BETWEEN TRINUCLEAR DIANIONS (M3(CO)11(2-),M=FE,RU,OS) AND METAL-CARBONYL DIMERS (MN2(CO)10 AND CP2M2(CO)6,M=CR,MO,W)

Reaction of mononuclear metal carbonyl anions with trinuclear clusters of group 8 (M3(CO)12, M = Fe, Ru, Os) at ambient conditions leads to four separate outcomes: (1) formation of the metal carbonyl dimer and the trinuclear dianion which occurs whenever the two-electron reduction potential for the dimer is more negative than for the trinuclear cluster, (2) formation of MFe2(CO)7- by elimination of Fe(CO)5 which occurs for M = Re(CO)5, Mn(CO)5, and CpMo(CO)3, (3) formation of the adduct, MRu3(CO)11-, which occurs for Re(CO)5, and (4) no reaction when the two-electron reduction potential for the trinuclear complex is more negative than for the dimer. For complexes where the two-electron potential for the cluster is more negative than for the dimer, reaction of M3'(CO)11(2-) with M2 to give M3'(CO)12 and 2M- is observed. The observed reactions allow an estimate of the two-electron reduction potentials for the trinuclear clusters. The kinetics of all of these reactions indicate a first-order dependence on the oxidant and on the reductant and are most consistent with outer-sphere electron transfer.