The reaction of (R3P)4-nCoXn (R = Ph, Et; X = Cl, Br; n = 1, 2) with Na2Ex (E = S, Se; x = 1, 2) in DMF or DMF/EtOH solution gave the hexacobalt cluster compounds, Co6(m3-E)8(PR3)6 (I), in high yields. The mol. structures of the compounds consist of regular or distorted Co6 octahedra. The neutral compounds I can be oxidized by I2 to form monocationic species with no change to the Co6 octahedral cores, while the monocationic compounds, [Co6(m3-E)8(PR3)6]+, can be reduced by sodium acenaphthalenide to form neutral species. Electrochem. properties of the compounds in CH2Cl2 were studied and electron-transfer sequences for the compounds were also described.

Key words: CHLORIDE, CRYSTAL STRUCTURE, BROMIDE, TRIPHENYLPHOSPHINE, TRIPHENYLPHOSPHINE, CLUSTER COMPOUND, COBALT COMPLEX, SULFIDE, SELENIDE, SODIUM SULFIDE