SYNTHESIS AND CHARACTERIZATION OF THIOLATE-BRIDGED DINUCLEAR NICKEL(II) COMPLEXES WITH THIOETHER PENDANT ARMS

Thiolate-bridged dinuclear nickel(II) complexes with N-[2-(2-pyridyl)ethyl]-N-[2-(methylthio)ethyl]-2-amino-ethanethiol (HL(a)) or N-[2-(2-pyridyl)ethyl]-N-[2-(ethylthio)ethyl]-2-aminoethanethiol (HL(b)), [Ni2(La)2](ClO4)2 (1) and [Ni2(Lb)2](ClO4)2 (2), have been synthesized and characterized by elemental analyses, infrared and electronic spectra, magnetic susceptibilities (80-300 K), and XANES. The crystal structures of 1 and 2 were determined by the single-crystal X-ray diffraction method at 118 and 293 K, respectively. The cation molecule has a thiolate-bridged dinuclear structure, in which each nickel ion is essentially.coordinated by a square-planar N2S2 donor set with a weak apical coordination of the pendant thioether group. The magnetic and spectral properties are discussed based on the crystal structures.