Synthesis and characterization of polystyrene-anchored monobasic bidentate Schiff base and its complexes with bi-, tri-, tetra- and hexavalent metal ions

Abstract

A new monobasic bidentate ON donor Schiff base PS–LH2 (where PS–LH2 = polystyrene-anchored Schiff base obtained by condensation of chloromethylated polystyrene (containing 1.17 mmol of chlorine per gram of resin cross-linked with 2% divinylbenzene), 2-hydroxy-1-naphaldehyde and 4-aminosalicylic acid has been synthesized. PS–LH2 reacts with metal complexes to form polystyrene-anchored complexes: PS–LHM(CH3Coo) · DMF (where M = Cu, Zn, Cd, UO2), PS–LHZr(OH)2(CH3Coo) · 2DMF, PS–LHFeCl2 · 2DMF, PS–LHM′(CH3Coo) · 3DMF (where M′ = Mn and Ni) and PS–LHMoo2(acac), where acacH = acetylacetone. The polystyrene-anchored complexes have been characterized by elemental analysis, IR, ESR and magnetic susceptibility measurements. The per cent reaction conversion of PS–LH2 to polystyrene supported coordination compounds lies between 30–95. Shifts of the azomethine ν(C=N) and phenolic ν(C–O) stretches are indicative of ON donor behaviour of the polystyrene-anchored ligands. The complexes, PS–LHCu(CH3Coo) · DMF, PS–LHFecl2 · 2DMF, PS–LHMn(CH3Coo) · 3DMF and PS–LHNi(CH3Coo) · 3DMF are paramagnetic, while PS–LHZn(CH3Coo) · DMF, PS–LHCd(CH3COO) · DMF, PS–LHUo2(CH3Coo) · DMF, PS–LHZr(OH)2(CH3COO) · 2DMF and PS–LHMoO2(acac) are diamagnetic. The copper(II) complex exhibits a square planar structure, zinc(II) and cadmium(II) complexes have tetrahedral structures, nickel(II), manganese(II), iron(III), dioxomolybdenum(VI) and dioxouranium(VI) complexes have octahedral structure and zirconium(IV) complex is pentagonal bipyramidal.