Infrared spectral studies on the stability of some binuclear transition metal—Schiff base complexes

Abstract

Some di-Schiff bases like N, N′- o-phenylene-bis-salicylaldimine (DSB 1), N, N′- m-phenylene-bis-salicylaldimine (DSB 2) and N, N′- p-phenylene-bis-salicylaldimine (DSB 3) have been synthesized by the condensation of salicylaldehyde with o-, m- and p-phenylenediamines, respectively. The synthesized complexes of Cu(II), Ni(II) and Co(II) with these ligands have been assigned their molecular structure on the basis of their elemental analyses, molecular weight determination, magnetic measurements, electronic spectra, molar volume and infrared spectral studies. The nature of bonding between metal ion and Schiff bases is studied by i.r. spectrophotometry. The shift in the band position of the groups involved in coordination has been utilized to estimate the coordination bond lengths. The value of the coordination bond length of Cu(II) complexes is shorter than the corresponding values for Ni(II) and Co(II) complexes.