Synthesis of bis{(2-dimethylphosphino)ethane-1-thiolato}bis(tert-butylthiolato)-molybdenum(IV) and its cluster-forming reactions with FeCl2 and CuBr

Reaction of Mo((SBu)-Bu-t)(4) with 2 equiv of HSCH2CH2PMe2 (Hdmsp) produced Mo(dmsp)(2)((SBu)-Bu-t)(2) (1) in high yield. Treatment of 1 with FeCl2 an d CuBr led to the formation of heterometallic clusters, [Mo(O)(dmsp)(2)](2) FeCl2 (2) and [MoBr(dmsp)(2)(mu(3)-S)Cu-2](2)(mu(2)-(SBu)-Bu-t)(2) (3), res pectively. The structures of 1-3 were determined by X-ray analyses. Complex 1 assumes a distorted octahedral geometry with a cis-disposition of two (B uS)-Bu-t ligands. In the structure of 2, an FeCl2 unit bridges two square-p yramidal Mo(O)(dmsp)(2) fragments through interactions between Fe and dmsp sulfur atoms, where the MoS2Fe quadrilateral is puckered. Formation of 3 in volves C-S bond cleavage of one (BuS)-Bu-t ligand of 1 and rearrangement of ligands between the Mo and Cu coordination sites, resulting in the structu re consisting of two MoCu2BrS(dmsp)(2) cluster units and two (BuS)-Bu-t bri dges.