Thiolate-Bridged Binuclear Nickel(II) Complexes with a Mixed-Spin State

Thiolate-bridged binuclear nickel(II) complexes with N,N-bis[2-(2-pyridyl)ethyl]-2-aminoethanethiol (HL), [Ni2(L)2](ClO4)2·1/2H2O and [Ni2(L)2](PF6)2, have been synthesized and characterized by elemental analyses, infrared and electronic spectra, and magnetic susceptibilities (80–300 K). The crystal structure of the perchlorate has been determined by the single-crystal X-ray diffraction method. The [Ni2(L)2]2+ cation has a novel binuclear structure where one of the nickel ions is coordinated by a square-planar N2S2 donor set and the other has a distorted square-pyramidal configuration (N3S2 donor set) with the pendant pyridyl nitrogen at the apex. From the above results, it was concluded that the present complexes are novel mixed-spin state containing a low-spin Ni(II) and a high-spin Ni(II) in the molecule.