SYNTHESIS AND STRUCTURE OF BIMETALLIC COMPLEXES WITH SIGMA,PI-BRIDGING THIENYL AND BENZOTHIENYL LIGANDS

The ligand properties of the organometallic fragment (eta(5)-SC4H3)Cr( CO)(3) were studied in the new sigma,pi-bimetallic complexes [Cr{eta(5 )-SC4H3)PtL2(SC4H3)}(CO)(3)] with L = CO and PMe3 1 or L-2 = dppe [1,2 -bis(diphenylphosphino)ethane] 2, [Cr{(eta(5)-SC4H3)Au(PPh3)}(CO)(3)] 3 and [Cr(eta(5)-SC4H3SnMe3)(CO)(3)] 4. Whereas the intermediates [Cr{ (eta(5)-SC4H3)PtL2Cl}(CO)(3)] (L = PMe3 or dppe) and [Pt((SC4H3)Cr(CO) (3)}(2)L-2] were too unstable to isolate and characterize, 4 slowly co nverted into [Cr{eta(5)-SC4H2(SnMe3)(2))(CO)(3)] 5. By contrast, the r eaction of lithiated [Cr(eta(6)-SC8H6)(CO)(3)] with [Pt(dppe)Cl-2] aff orded the stable trinuclear complex, [Pt{(eta(6)-SC8H5)Cr(Co)(3)}(2)(d ppe)] 6.