Synthesis, characterization, biological screening and determination of stability constants of N,N\u2032-Bis[1-(4-chlorophenyl)ethylidene]ethane-1,2-diamine

Abstract

A Schiff base ligand, N,N′-bis[1-(4-chlorophenyl)ethylidene]ethane-1,2-diamine (SBL), was synthesized by condensation of 4-chloroacetophenone with ethylenediamine in methanol in the presence of H2SO4 as catalyst. The structure of SBL was elucidated by spectroscopic (1H-NMR, 13C-NMR, IR and MS) and elemental analyses, and also confirmed by XRD. The SBL was used to prepare metal complexes 1-2 with Pb+2 and Cd+2, respectively. The structures of the complexes were elucidated by IR, MS and elemental analyses. On the basis of electronic spectra and magnetic moment data, octahedral geometry was proposed for the synthesized complexes 1-2. The conductivity data showed the non-electrolytic nature of the complexes 1-2. The SBL and complexes 1-2 were subjected to measure their biological potential against Staphylococcus aureus, Bacillus subtilis and Escherichia coli bacteria. SBL showed non-significant anti-bacterial potential whereas complexes showed moderate potential as compared to standard impinium. In the toxicity with brine shrimp larvae, complexes showed more toxic effect than the SBL. In the experiments to determine the stability constants of SBL with CuCl2, Cu(OAc)2, CoCl2 and Co(NO3)2; SBL showed highest stability constants with Cu(OAc)2 which is 1.550 × 107 at 1:1 (L:M) and second highest with Co(NO3)2 which is 6.861 × 106 at 3:2 (L:M).