The paramagnetic compounds [Ni-2(HMTA)(i-BU2PS2)(4)](I) and [Ni-2(TEDA)(i-Bu2PS2)(4)] (II) (mu(eff) = 3.11 and 3.23 mu(B), respectively) were synthesized by reacting diamagnetic Ni(i-Bu2PS2)(2) with hexamethylenetetramine (HMTA) and triethylenediamine (TEDA) in ethanol. The crystal structure of I was established by single-crystal X-ray diffraction analysis (CAD4 diffractometer, MoKalpha radiation, 1483 F-hkl, R = 0.0648). The crystals are monoclinic: a = 35.212(7) Angstrom, b = 9.313(2) Angstrom, c = 22.622(5) Angstrom; P = 129.97(3)degrees, V = 5685(2) Angstrom(3), Z = 4, p(calcd) = 1.281 g/cm(3), space group C2/c. The structure is built of discrete binuclear molecules. The coordination polyhedron of the Ni atom is a distorted tetragonal pyramid with four S atoms of two bidentate cyclic ligands i-Bu2PS2- in the base and the N atom of the bidentate bridging ligand HMTA at the axial vertex. Complexes I and II have similar electronic reflection spectra, which agrees with the C-4v, symmetry of the ligand field.