Synthesis and spectral characterization of Schiff-base complexes derived from alanine and 2-acetylpyridine with some divalent metal acetates

Abstract

Schiff-base complexes [ML(H₂O)₂(Ac)]nH₂O (M = Co(II), Ni(II) and Zn(II); L = Schiff-base ligand derived from 2-acetylpyridine and alanine and n = 1–3/2) were synthesized and characterized by elemental analysis, spectral (FTIR, UV/Vis, MS, ¹H-NMR), thermal (TGA), conductance and magnetic moment measurements. The results suggest octahedral geometry for all the isolated complexes. IR spectra show that the ligand coordinates to the metal ions as mononegative tridentate through pyridyl nitrogen, azomethine nitrogen and carboxylate oxygen after deprotonation of the hydroxyl group. Semi-empirical calculations PM3 and AM1 have been used to study the molecular geometry and the harmonic vibrational spectra to assist the experimental assignments of the complexes.

Keywords:

• Schiff base
• Alanine
• Metal complexes
• 2-Acetylpyridine
• Co(II)
• Ni(II) and Zn(II)
• Semi-empirical calculations