The reaction of nickel(II)chloride with γ-mercapto-propylamine in ethanolic solution gives the complex [Ni3(MPA)4]Cl2(MPA=NH2-(CH2)3-S). The complexes [Ni3(MPA)4]X2(X=Br, I, ClO4) can be synthesized from the chloride complex by addition of the sodium salt in aqueous solution. The crystal structure consists of discrete divalent trinuclear cations and chloride anions. Each sulphur atom of the ligand acts as a bridge between two nickel atoms, and the nitrogen atoms complete the coordination around the terminal nickel atoms. The geometry around the metal atoms is square-planar. The electronic and IR spectra of the complexes [Ni3(MPA)4]X2(X=Br, I, ClO4) indicate that all these compounds are composed of the [Ni3(MPA)4]2+ and X- ions. © 1984.