AMBIDENTICITY OF A TRIDENTATE OXYGEN NITROGEN DONOR TOWARDS BIVALENT AND TRIVALENT TRANSITION-METAL IONS

N-salicylidene anthranilamide (H2SAA) and its Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complexes were prepared and characterized by physicochemical and spectroscopic data. H2SAA enolizes to give a dibasic ONO donor set in the divalent metal complexes. It also binds to the trivalent metal ions in a nonenolized form using a monobasic ONN donor set. Co(II) is oxidized to Co(III) during complexation. Octahedral geometries are proposed for Cr(III), Mn(II), Fe(III) and Co(III) complexes, while square planar geometries are suggested for the Ni(II) and Cu(II) complexes. Phenoxide bridging in the Cr(III) and Fe(III) complexes and enoxide bridging in the Ni(II) and Cu(II) complexes is proposed.