The Effect of Steric Condition in Cobalt(II), Nickel(II) and Copper(II) Complexes with Schiff Bases Obtained from Salicylaldehyde Derivatives and Diphenylmethylamine

Abstract

Abstract Cobalt(II), nickel(II) and copper(II) complexes with N-diphenylmethyl-ring-substituted salicylideneiminates (abbreviated as X–Sal–Dpm) have been synthesized, in order to examine the steric and electronic effect of a substituent diphenylmethyl group on the structure of the metal complexes. Compounds of the type M(X–Sal–Dpm)2 and their adducts of the type M(X–Sal–Dpm)2·nL have been isolated in crystals, n being 2 or 4 and L being benzene, acetone or pyridine. Both in the solid state and in non-donor solvents, the complexes Co(X–Sal–Dpm)2 have a tetrahedral configuration, and Ni(X–Sal–Dpm)2 and Cu(X–Sal–Dpm)2 have a square-planar configuration, irrespectively of substituents X. The results so far available seem to indicate that the steric hindrance caused by the substituent diphenylmethyl group against the square-planar configuration of the metal complexes may be smaller than that by isopropyl group.