Synthesis and Characterization of New Lead(II) and Organotin(IV) Complexes of Schiff Bases Derived from Histidine and Methionine

Har Lal Singh,J B Singh

doi:10.1155/2012/568797

Abstract

New Schiff base (HL) ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR). The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2) to from metal complexes (Pb(II)(L)2 and Bu2Sn(L)2, where L is the Schiff base ligands of histidine and methionine). The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV) and lead(II) complexes.

Highlights

Metal Schiff-base complexes have continued to play the role of one of the most important stereochemical models in main group and transition metal coordination chemistry due to their preparative accessibility, diversity, and structural variability
The Schiff base (HL) and metal complexes are subjected to elemental analysis
New metal complexes were synthesized by the reaction of dibutyltin(IV) oxide and lead(II) acetate with Schiff bases being carried out in 1 : 2 molar ratios using anhydrous benzene and absolute methanol in 3 : 1 ratio as solvent

Summary

Introduction

Metal Schiff-base complexes have continued to play the role of one of the most important stereochemical models in main group and transition metal coordination chemistry due to their preparative accessibility, diversity, and structural variability. In continuation of recent reports from this laboratory on some amino acid Schiff base metal complex systems [13,14,15,16], the present studies, ligand (L1H–L4H) is obtained by the condensation reaction between amino acids (L-histidine, DL-methionine) and isatin, chloroisatin with this hope that it may provide us valuable theoretical information for exploring metal-based bacteriostatic and carcinostatic pharmaceuticals with high efficacy and low toxicity In this effort, we have introduced an azomethine (–C=N–) linkage with the concern that it may permit a notable variety in the remarkable chemistry and behavior of such compounds.

Methods

Results

Conclusion