The crystal and molecular structure of the title compound, [Ni(phen)(2)(CH3)(2)CHOCSS](CH3)(2)CHOCSS has been determined by X-ray diffraction. The brown crystal is triclinic of space group P1, with parameters a=11.790(2), b=12.410(3), c=12.680(3)Angstrom, alpha=92.49(3), beta=96.54(3), gamma=117.43(3), and Z=2. The compound contains a six-coordinate cation and an isopropyl xanthate anion (CH3)(2)CHOCSS-, the central Ni atom is chelated by four nitrogen atoms of two phenanthroline ligands and two sulfur atoms of an isopropyl xanthate ligand. The TG data indicate that it decomposed completely at 734degreesC.