Synthetic, Spectral, Thermal and Biological Studies of Lanthanide (III) Complexes with a Schiff Base Derived from 3-N-Yetaylpiperidino-4-Amino-5-Yercapto-1,2,4-Triazole

Abstract

A series of Ln(III) complexes of the type [Ln (BPSYT)2-NO3l. nH2O (where Ln = La, Ce, Pr. Nd. Sm. Eu, Gd, Tb. DY, Er, Yb. Y; HPSYT = 3-N-methylpiperidino-4-salicylideneamino-5-mercapto-1,2,4-triazole and n = 1-3) have been syntheeized by the direct reaction of 3-N-methylpiperjdino-4-salicylidene-amino-5-mercapto-l,2,4-triazole with I. n(III) nitrate in dry alcohol. The complexes have been characterized by elemental analyses, molar conductance, magnetic measurements. electronic, infrared, and 1H NMR studies. The elemental analyses reveal 1:2 stoichiometry with respect to metal:ligand. Molar conductance studies indicate the non-electrolytic nature of the complexes. The spectral studies show the ligand HPSNT and nitrate groups bound to the Ln(III) ion in a bidentate fashion. It is proposed that, the complexes exhibit the coordination number six. Thermal studies have been carried out for the La(III), Nd(III) and Dy(III) complexes. The parameters. such as energy of activation (Ea), change in enthalpy (ΔH#), change in entropy (ΔS#) and change in free energy (ΔG#) were established for the above complexes. The ligand and its Ln(III) complexes were screened for antibacterial and antifungal activity. It was found that in few of the Ln(III) complexes activity of the ligand gets increased.