Transition metal complexes with thiosemicarbazide-based ligands. Part 49. New complexes of iron(III) with deprotonated tridentate Schiff base pyridoxal derivatives

Three new bis(ligand) iron(III) complexes were prepared with the deprotonated ONX ligands (X = O,S,N), pyridoxal semi-, thiosemi- and S-methylisothiosemicarbazones (H2L1, H2L2 andH2L3, respectively) of the formulas [Fe(HL1,2)L1,2]. 4H2O and [Fe(HL3)2]OAc. 2H2O. The compounds were characterized by elemental analysis, conductometric and magnetochemical measurements, as well as by IR and UV-vis spectra. Detailed voltammetric investigations were carried out in DMF solutions in the presence of several supporting electrolytes to study the nature of the electrochemical processes and solution equilibria.