“…Binuclear complexes of polyfunctional diazine ligands involving ~o l e s , ~ triaz~les,~' and hydrazines [28][29][30][31][32][33] have binuclear centres in which the metal atoms are invariably antiferromagnetically coupled via a superexchange mechanism. In copper(r1) complexes of some quadridentate phthalazines where, in addition to the diazine bridge, a hydroxide group also bridges the two metal centres, exchange integrals fall in the range -2J = 200-800 cm-' with a linear relationship between -W and Cu-O-Cu angle for systems with dxl -, , 2 copper ion ground states.'…”