[Co3(CO)9(mu-3-CX)](X = H, Cl) react with S2CPR3 (R = cyclohexyl, Cy or isopropyl, (i)Pr) in CH2Cl2 to give heptacarbonyltricobalt clusters [Co3(CO)7(mu-3-CX)(mu-2-S2CPR3)] in which the S2CPR3 act as four-electron ligands, bridging a Co-Co cluster edge in a sigma(S), sigma(S') fashion, as shown by an X-ray determination on a crystal of the derivative with X = H, R = Cy. The five-membered CoSCSCo ring is nearly perpendicular to the Co3 triangle (i.e. axial), in contrast to the equatorial disposition usually found in related complexes with phosphorus ligands.
