Preparation and properties of [NiII(BEES)(Cl)](BPh4):: a NiII complex in a mixed nitrogen/thioether coordination environment

The synthesis and properties of the Ni-II complex [Ni-II(BEES)(Cl)](BPh4) are described. The ligand bis-2-beta-benzylthioethylaminoethylsulfide. HCl ((BEESHCl)-H-.) was prepared in good yield in three steps from bis-ethylaminosulfide and acetyl chloride. Complexation of Ni-II in the presence of chloride affords [Ni-II(BEES)(Cl)](BPh4). which contains high-spin Ni-II in a pseudo-octahedral coordination environment, ligated by amine nitrogens, thioether sulfurs, and a chloride. The complex is irreversibly reduced at a potential of -1.24 V vs. SCE. The complex displays four d --> d bands in the UV-Vis. Reduction of Ni-II --> Ni-I by Na/acenaphthylene leads to complete decomposition of the complex. (C) 2002 Elsevier Science B.V. All rights reserved.