Synthesis of Ge2NiS4 clusters and the thermal transformation to a Ge4Ni6S12 cluster

摘要

The reaction of Ni(dppe)Cl-2 and syn-[DmpGe(SLi)(mu-S)(2)Ge(SLi)Dmp] prepared in situ from syn-[DmpGe(SH)(S)(2)Ge(SH)Dmp] (1) and n-BuLi (2 equiv) afforded the Ge2NiS4 cluster, [DmpGe(mu-S))2(mu-S)(2)Ni(dppe) (2) (Dmp = 2,6-dimesitylphenyl). The nickel in 2 assumes a slightly distorted square planar geometry. However, another Ge2NiS4 cluster, [DmpGe(mu-S)12(U-S)2Ni(PPh3)2 (3) obtained from a similar reaction with Ni(PPh3)(2)Cl-2, contains the nickel in a tetrahedron. When 3 was heated to 120 degrees C in toluene, a novel Ge4Ni6S12 cluster [DmpGe(mu-S)(3)](4)Ni-6 (5) was obtained. In cluster 5, six nickels form an octahedron with the nickels occupying its vertexes, and four DmpGeS(3) units cap half of the trigonal faces.