The reactions of [NiX_2(PPh_3)_2] (X = F, Cl, SCN) with B_(10)H_(10) ~(2-) in CH_2Cl_2 were investigated and the cluster [(μ-Cl) (Ph_2PC_6H_4)_2Ni_2B_(10)H_6Cl(PPh_3)]·0.25CH_2Cl_2 (1) was characterized by elemental analysis, IR, time-of-flight secondary ion mass spectrum and single crystal diffraction analysis. Crystal data for 1: triclinic crystal system, space group P2_1/c with cell dimensions, a = 1.1703(2)nm, b = 2.1082(4) nm, c = 2.2068(8)nm β=99. 82(2) °, V=5.3622(2)nm~3, Z = 4, F(000) = 2274, D_(calcd) = 1.373 g/cm~3. R_1=0.0358, wR_2 = 0.0807. The cluster possesses closo twelve- vertex configuration and has two ortho-cycloboronated Ni-P-C-C-B five- membered rings. There is a Cl-bridge between two Ni atoms. The structure analysis shows that the cyclization can strengthen the nickel-to-boron bonding.

Key words: NICKEL COMPOUNDS, BORANE P, CLUSTER COMPOUND, CONFIGURATION, ELEMENTAL ANALYSIS, TIME-OFF FLIGHT MASS SPECTROMETRY, CRYSTAL STRUCTURE