Control of Exchange Interactions in Trinuclear Complexes Based on Orthogonal Magnetic Orbitals

The reaction of copper(II) acetate with the tetradentate Schiff base like ligand H4L {(E,E)-[{diethyl 2,2′-[4,5-dihydroxy-1,2-phenylenebis(iminomethylidyne)]bis(3-oxobutanoate)}] leads to the formation of the square planar N2O2 coordinated complex [H2CuL]. Reaction of two equivalents of this complex with copper(II) acetylacetonato or vanadyl(IV) acetylacetonato yields the trinuclear complexes [V(O)Cu2L2][N(nBu)4]2·2MeOH (1) and [Cu3L2][N(nBu)4]2·2DMF (2). Both complexes were characterised by using magnetic measurements and X-ray crystallography. Special attention was given to the spin-exchange coupling through the bridging phenylene ring. The principle of strict orthogonality of the magneti…