Synthesis, spectroscopic and thermal analysis of a 1,10-phenanthroline derivative schiff base and its transition metal complexes

In this study, we were synthesized 1,10-phenanthroline derivative Schiff base ligand and its some transition metal complexes. Their structures have been investigated and characterized. Firstly, 5-salicylideneimino-1,10-phenanthroline was synthesized from 5-amino-1,10- phenanthroline and salicylaldehyde. Then, complexes of Schiff base ligand, LH, with Ni(II), Cu(I), Co(II), Fe(III) and Cu(II) ions have been synthesized in EtOH and yielded 40 %, 67 %, 49 %, 63%, 69% respectively. Then, the structures of the ligand and its complexes have been characterized by elemental analysis, FTIR, 13C NMR, 1H NMR, LC-MS spectrophotometers, magnetic susceptibility TGA/DSC/DTG. Regarding spectroscopic studies, for Co(II) complex, octahedral, for Ni(II) and Cu(II) complexes, tetrahedral structure are proposed. Geometric structure of Fe(III) and Cu(I)complexes are not explained because of the discrepancy between magnetic and spectroscopic data. Lastly, the ligand and the Ni (II), Cu (I), Co (II), Fe (III) and Cu (II) complexes have been studied potentiometrically. Protonation constants of the ligand were calculated with a potentiometric titration method and the TITFIT program. Protonation constants of LH2 + which have been determined by potentiometric titration in solution are log K1 = 10.99, log K2 = 8,00. The metal to the ligand ratio of the Ni(II), Cu(I), Co(II), Cu(II) complexes was found to be 1:2.