SYNTHESIS, SPECTRAL AND THERMAL STUDIES OF FE(III), CO(II), NI(II), CU(II) AND ZN(II) COMPLEXES OF SCHIFF-BASES DERIVED FROM O-AMINOBENZYL ALCOHOL

Several new complexes of isomeric Schiff bases derived from salicylald ehyde (L') or o-hydroxyacetophenone (L '') or o-hydroxynaphthaldehyde. (L(triple prime) and o-aminobenzyl alcohol with Fe(III), Co(II), Ni(I I) and Zn(II) have been synthesized and characterized on the basis of elemental analyses, molar conductance, electronic and infrared spectra l studies and magnetic susceptibility measurements. Thermal [thermogra vimetric analysis (TGA), differential thermal analysis (DTA) and DTG ( derivative thermogravimetric)] studies have also been carried out. The Schiff bases behave as tridentate dibasic ONO donors forming complexe s of the types M(L).nH(2)O (where M = Ni or Co, n = 3; M = Zn, n = 1), [FeCl(L)](2) and [CuL](2). The complexes of Cu(II) and Fe(III) exhibi t subnormal magnetic moments at ambient temperature and the effective magnetic moments decrease significantly as the temperature is lowered, indicating the presence of antiferromagnetic exchange. The exchange i nteraction constant (-J) of the Cu(II) complexes is in the range 231- 373 cm(-1). On the basis of spectral and magnetic studies, a dimeric s quare-planar and square-pyramidal geometry for the Cu(II) and the Fe(I II) complexes, respectively, octahedral for the Co(II) and the Ni(II), and tetrahedral geometry for the Zn(II) complexes have been suggested .