Synthesis, characterization, structure, DNA binding aspects and molecular docking study of a novel Schiff base ligand and its bis(μ-chloro) bridged Cu(II) dimer

Abstract

A novel Schiff base ligand, 2-(benzothiazol-2-yl-hydrazono)-1,2-diphenyl-ethanone (LH), has been synthesized out of the 1:1 condensation of benzil and 2-hydrazino benzothiazol in methanol. Reaction of equimolar proportion of LH and pre-activated CuCl2·2H2O in methanol generates bis(μ-chloro)bis(2-(benzothiazol-2-yl-hydrazono)-1,2-diphenyl-ethanoate)-dicopper(II), [Cu2(μ-Cl)2(L)2] (1) in copious yield. C, H and N microanalyses, ESI-MS, FT-IR, UV–Vis spectral studies have been undertaken to characterize LH and 1. The X-ray crystal structure of 1 has been determined. LH undergoes keto-enol tautomerism. The tautomeric aspects of LH have been corroborated through DFT calculations. LH binds to copper(II) in its enolate form to give rise the symmetric bis(μ-chloro) bridged copper(II) dimer. Both LH and 1 show the efficacy to bind CT DNA. The binding constants and the thermodynamic binding parameters have also been determined. A favourable major groove binding efficacy has been exposed for both the ligand and complex through molecular docking.