COMPLEXES OF NICKEL(2) WITH CYLIC TETRADENTATE SCHIFF BASES DERIVED FROM 2-MERCAPTOANILINE

The synthesis, electrical conductivity, and electronic spectra are described for a number of complexes of nickel(II) with the new cyclic planar tetradentate ligands S,S′-o-xylyl-2,3-butanedione bis(2-mercaptoanil) and S,S′-o-xylyl-1,2-cyclohexanedione bis(2-mercaptoanil) and the related noncyclic ligand S,S′-dibenzyl-2,3-butanedione bis(2-mercaptoanil). The complexes are prepared by the action of α,α′-dibromo-o-xylene or α-bromotoluene on the nickel(II) complexes of the Schiff base of the appropriate α-diketone and 2-mercaptoaniline. Bromide, iodide, and thiocyanate salts have been isolated. All of the complexes show high-spin magnetic moments and are 1:1 electrolytes in acetonitrile. Their electronic spectra have been assigned on the basis of a model of tetragonally distorted octahedral symmetry, and the ligand field strengths of the new ligands and the tetragonal splitting parameters have been estimated and compared with those of related ligands. © 1968, American Chemical Society. All rights reserved.