HETERODINUCLEAR COMPLEXES OF RHENIUM AND MOLYBDENUM WITH BRIDGING S2CPR3 LIGANDS

Mononuclear complexes fac-[Re(CO)3(S2CPR3)Br] (R = cyclohexyl (Cy) (1a ) or isopropyl ((i)Pr) (1b)) react with [Mo(CO)3(NCMe)3] to afford din uclear complexes of formula [ReMo(CO)6(mu-Br)(mu-S2CPR3)] (R = Cy (2a) or (i)pr (2b)). Treatment of complexes 2 with monodentate phosPhorus donors such as PEt3 or P(OMe)3 displaces one carbonyl ligand from the molybdenum atom, to afford pentacarbonyls [ReMo(CO)5(mu-Br)(mu-S2CPR3) (L)] (3a-3d). Reactions of 2 with bidentate phosphorus donors displace one CO group from molybdenum and cleave one Re-S bond to give pentaca rbonyls [ReMo(CO)5(mu-Br)(mu-S2CPR3)(mu-L-L)] (4a-4d) (L-L = tetraethy lpyrophosphite or bis(dimethylphosphino)methane), in which the S2CPR3 bridges have changed their coordination mode from eta2(S,S')eta3(S,C,S ,) to eta1(S)eta3(S,C,S,).