BSA binding studies of Co(II), Ni(II) and Cu(II) metal complexes of Schiff base derived from 2-hydroxy-4-methoxybenzaldehyde and 2-amino-6-methylbenzothiazole

Abstract

The synthesis of Schiff base HL has been done by taking an equimolar ratio of 2-hydroxy-4-methoxybenzaldehyde and 2-amino-6-methylbenzothiazole. Ligand HL has been characterized by elemental analysis, IR, 1H NMR, 13C NMR and ESI-mass spectrometry. The metal complexes 1-6 have been synthesized by the reaction of ligand HL with hydrated Co(II), Ni(II) and Cu(II) chlorides in ethanol, in the ligand to metal molar ratio 1:1 and 2:1. The synthesized metal complexes 1-6 were characterized by elemental analysis, molar conductance, electronic spectra, IR, UV-visible and EPR spectra. TGA has been done to check the thermal stablity of ligand as well as metal complexes. Spectral data reveals that the ligand HL acts as uninegative bidentate for all metal complexes. The geometries of metal complexes 1-6 have been given on the basis of spectroscopic studies and optimized by density functional theory. The fluorescence techniques have been used to study the interactions of metal complexes towards bovine serum albumin (BSA). The results revealed that the fluorescence static quenching of BSA by metal complexes 1-6 and entropy driven hydrophobic interactions has been seen which could be useful for further drug design.