Binuclear copper(I) borohydride complex containing bridging bis(diphenylphosphino) methane ligands: Polymorphic structures of [(?2-dppm)2Cu2(?²-BH4)2] dichloromethane solvate

Bis(diphenylphosphino)methane copper(I) tetrahydroborate wasynthesized by ligandsxchange in bis(triphenylphosphine) copper(I) tetrahydroborate, and characterized by XRD, FTIR, NMR spectroscopy. According to XRD the title compound has dimerictructure, [(?2-dppm)2Cu2(?2-BH4)2], and crystallizes as CH2Cl2 solvate in two polymorphic forms (orthorhombic, 1, and monoclinic, 2) The details of molecular geometry and the crystal-packing pattern in polymorphs were studied. Theare Twisted Boat-Boat conformation of the core Cu2P4C2 cycle in 1 is found being more stable than Boat-Boat conformation in 2.