Synthesis and characterization of mixed-metal sulfide clusters with the cubane-type PtMo3S4 core

The reaction of the incomplete cubane-type duster [Mo-3(mu(3)-S)(mu-S)(3)(H 2O)(9)]Cl-4 (1) and [Pt(dba)(2)] (dba = 1,5-diphenyl-1,4-pentadien-3-one) i n MeOH gave a brown precipitate (4) that contains platinum and molybdenum i n the atomic ratio of 1 :3. Further treatment of 4 with 3 equiv of dppe (dp pe = 1, 2-bis(diphenylphosphino)ethane) gave the cubane type cluster [PtMo3 (mu(3)-S)(4)Cl-4(dppc)(3)] (5) in 37% yield, whose molecular structure was unambiguously characterized by X-ray diffraction study of 5.2CH(2)ClCH(2)Cl .2H(2)O. A similar reaction of 4 with 4 equiv of dppe afforded the cationic cluster [PtMo3(mu(3)-S)(4)Cl-3(dppe)(4)]Cl (6) in 29% yield, which was cha racterized spectroscopically. The Pd-Mo and Ni-Mo analogues of the above Pt -Mo clusters, [PdMo3(mu(3)-S)(4)Cl .(dppe)(4)]Cl . CH2Cl2 (7) and [NiMo3(mu (3) -S)(4)Cl-4(dppe)(3)] (8), were also synthesized by the reactions of the corresponding aqua clusters with dppe.