The title complex [Ni(IDB)~2][C~6H~4(OH)COO]·ClO~4· CH~3CH~2OH· H~2O [IDN=N,N-di(2-benzimidazolylmethyl) imine] has been synthesized and characterized by elemental analysis, IR and UV-Vis spectra. The crystal structure has been determined by single crystal X-ray diffraction. The crystal of mononuclear Ni(Ⅱ) complex is triclinic system, space group, P1, a=1.1010(2) nm, b=1.3800(3) nm, c=1.5550(3) nm, α=100.75(3)°, β=102.97(3)°, γ=107.56(3)°, V=2.1113(7) nm^3, Z=2, F(000)=952, D~c=1.438g/cm^3, M~r=914.01, μ=0.591 mm^-^1. The final R[I>2σ(I)]:R~1=0.0591, ωR~2=0.1325; R(all data):R~1=0.1302, ω R~2=0.1572. The nickel (Ⅱ) atom in the cation has distorted octahedronal coordination geometry and is six-coordinated by six nitrogen atoms: four nitrogen atoms of the benzimidazole groups and two imine nitrogen atoms from the ligand IDB. The catalytic activity of the complex in the hydrolysis of urea was measured with gas chromatography.

Key words: NICKEL COMPLEX, CRYSTAL STRUCTURE, UREA, HYDROLYSIS, BENZIMIDAZOLE P, GAS CHROMATOGRAPHY