Synthesis of syn-2,4-dimercapto-1,3,2,4-dithiadigermetane and its application to Ge2PdS4 cluster synthesis.

The sulfurization of DmpGeH(3) (Dmp=2,6-dimesitylphenyl) afforded the trinuclear germanium sulfide DmpGe(mu-S)(mu-S)(2)Ge(SH)-Dmp and a series of polythiadigermabicyclo[x.1.1]alkanes (x=3, 4, 5). The reduction of the S--S bonds of these germabicycloalkanes by NaBH(4) at 0 degrees C afforded the dinuclear mercaptogermane syn-[DmpGe(SH)(mu-S)(2)Ge(SH)-Dmp] (5) in good yield. The reaction of [Pd(dppe)Cl(2)] (dppe=1,2-bis(diphenylphosphanyl)ethane) and the dilithium salt of 5 prepared in situ by the addition of nBuLi (2 equiv) gave the Ge(2)PdS(4) cluster DmpGe(mu-S)[(mu-S)(2)Pd(dppe)], in which the dithiadigermetanedithiolate is bound to the Pd atom at the two thiolato sulfur atoms. The same reaction with [Pd(PPh(3))(2)Cl(2)] gave another Ge(2)PdS(4) cluster, DmpGe(mu-S)[(mu-S)(2)Pd(PPh(3))], but with the dithiadigermetanedithiolate and the Pd center conjoined through a mu-S atom between the two germanium atoms in addition to the two thiolato sulfur atoms to form a highly distorted cluster core. The formation of two different types of Ge(2)PdS(4) clusters represents the usefulness of 5 in the synthesis of various polynuclear complexes composed of germanium and transition metals.