Metal complexes of hydrogenated Schiff bases

Abstract

N-Substituted o-hydroxybenzylamines formed by the hydrogenation of the C=N bond in N-arylsalicylideneimines were prepared, and found to be slightly stronger bases but much weaker acids than the corresponding Schiff base. They react with copper(II) acetate give crystalline derivatives of empirical constitution (copper(II) : ligand : acetate). Magnetic moments and infrared measurements indicate that the complexes are associated in the solid state. Reaction with copper(II) nitrate yields complexes of two types dependent on the aryl substituent. The o-tolyl derivative contains a covalently bound nitrato group while other derivatives have ionic nitrate groups. The quadridentate ligand N,N?-ethylenebis(o-hydroxybenzylamine) reacts readily with copper(II), nickel(II), and zinc(II) ions to give crystalline products which are probably associated in the solid state.