ELECTROCHEMISTRY OF [(RU3(CO)9(MU-3-ETA-2-CCTBU))2HG] AND [RU3(CO)9(MU-3-ETA-2-CCTBU)HGX] (X=RE(CO)5 OR MOCP(CO)3)

The electrochemical reduction of [{Ru3(CO),(mu3-eta2-C=C(t)Bu)}2Hg] and [Ru3(CO)9(mu3-eta2-C=C(t)Bu)HgX] (X=Re(CO)5 or MoCp(CO)3) has been investigated at both Pt and Hg electrodes in tetrahydrofuran (THF) at different temperatures by means of cyclic voltammetry and coulometry. All the compounds undergo chemically irreversible reduction followed by the formation of [Ru3(CO)9(mu3-eta2-C=C(t)Bu)]- anion, mercury, and organometallic radical X. at essentially the same potential. Despite the isolobal relationship between the proton in [Ru3(mu-H)(CO)9(mu3-eta2-C=C(t)Bu)] and the HgX fragment, the reduction potentials of title compounds are significantly less negative (ca. 0.3 V) suggesting that the LUMO in these complexes is at lower energy than in the corresponding hydride, and has significant mercury character.