Synthesis and reactivity of the copper(I) complex containing bis(diphenylphosphino)methane bridging ligands — structure of [Cu4(μ4-S)(dppm)4](PF6)2·CH2Cl2

The tetranuclear copper(I) complex [Cu4(μ4-S)(dppm)4](PF6)2·CH2Cl2 was obtained by the reaction of the ligand reduction product [Cu(dppm)(NO3)]2 [dppm=bis(diphenylphosphino)methane] with carbon disulfide. The title complex was also analyzed by cyclic voltammetry and by ES MS, XPS and 31P NMR spectroscopic techniques. X-ray data show that the dppm ligand coordinates in a bridging bidentate manner and an unusual μ4-S ligand coordinates to the Cu(I) atoms in the newly prepared tetranuclear copper complex, with free [PF6]− counterions. The CuP distances vary from 2.262(3) to 2.308(3) Å, the CuCu separation between 2.88(2) and 3.17(1) Å. The copper(I) ions have a trigonal planar geometry with a P2S donor set.