Dependence of magnetic coupling on ligands at the axial positions of Ni in phenoxido bridged dimers: experimental observations and DFT studies.

A nickel(ii) complex [NiL(CHCN)](ClO)·2CHCN (1) has been synthesized by using a tridentate reduced Schiff base ligand, HL, 2-[(3-methylamino-propylamino)-methyl]-4-nitrophenol and Ni(ClO)·6HO. Stoichiometrically controlled addition of NHSCN to the acetonitrile-water solution of 1 produced two other complexes, [NiL(μ-NCS)(CHCN)](ClO)·CHCN (2) and [NiL(NCS) (CHCN)] (3) by replacing one and two coordinated CHCN by NCS, respectively. The dinuclear Ni complexes 1 and 3 are structurally very similar containing a diphenoxido bridge between the Ni ions.