Physicochemical and Spectroscopic Study of Co(II), Ni(II), Cr(III), and Fe(III) Cholyltaurine Adducts

Abstract

Physical spectroscopic characteristics of Co(II), Ni(II), Cr(III), and Fe(III) cholyltaurine adducts have been studied. IR and Raman spectra confirmed that the cholyltaurine compound acted as a mononegative bidentate chelating agent. Nitrogen atom of the NH group and O^– of deprotonated sulphonate group acted as chelation sites towards the metal ions. UV-Vis spectra and magnetic moments block measurements confirmed that all complexes had the octahedral geometry. Water, Cl^–, and NO₃^– acted as secondary chelates. The positron annihilation lifetime (PAL) technique was applied to investigate the structural changes of cholyltaurine ligand and its complexes. The results indicated that the average defect density in the studied ligand and its complexes was efficiently correlating with their molecular weight.