Synthesis of asymmetric heterotrimetallic gold clusters containing Mo, W, and Mn

A series of new heterotrimetallic gold clusters, [(OC)3M(mu-S2CPR3)(mu-AuPPh3)Mo(CO)3](M = Mn, R = Cy, 3a; R = Pri, 3b; M = Re, R = Cy, 3c; R = Pri, 3d) and [(L)(OC)2Mo(mu-S2CPCy3)(mu-AuPPh3)M(CO)3](M= Mo, L =3-allyl, 6a; L = NO, 6b; M= W, L =3-allyl, 6c; L = NO, 6d), have been synthesized in good yields by the reactions of ClAuPPh3 with the corresponding homo- or heterobinuclear anions, [(OC)3M(mu-S2CPR3)Mo(CO)3] – and [(L)(OC)2Mo(mu-S2CPCy3)M(CO)3]–, formed respectively by the reduction of the complexes [(OC)3M(mu-Br)(mu-S2CPR3)Mo(CO)3] and [(L) (OC)2Mo(mu-Br)(mu-S2CPR3)M(CO)3] with Na/Hg. The new complexes have been characterized spectroscopically and the molecular structures of 3a, 6a, and 6c have been determined by X-ray crystallography, revealing remarkable structural differences between the trimetallic cores.