Synthesis, characterization, crystal structure and DNA-binding study of four cadmium(II) pyridine-carboxamide complexes

Abstract

Treatment of perchlorate or nitrate salt of cadmium(II) with carboxamide derivatives (L) generated four novel mononuclear metal complexes, represented as [Cd(L )4](ClO4)2 (1a and 1b) and [Cd(L)2(ONO2)2] (2a and 2b) in appreciable yields (L = L1 = N-(furan-2-ylmethyl)-2-pyridine carboxamide and L = L2 = N-(thiophen-2-ylmethyl)-2-pyridine carboxamide). The complexes have been characterized by FT-IR, UV-Visible, elemental analysis and single crystal X-ray crystallographic analysis which revealed eight coordinated cadmium ions, but in different coordination environments, depending on the counter anion used. In addition, electronic absorption, fluorescence spectroscopy and viscosity measurements revealed a significant interaction of the four complexes with CT-DNA via intercalative/groove binding mode. The intrinsic binding constant Kb obtained varies from 0.4 × 10 4 to 1.11 × 10 5 M−1. The results suggest that neutral complexes 2a and 2b bind to DNA in an intercalative mode. On the other hand, cationic complexes 1a and 1b bind with DNA via weak electrostatic/covalent interaction

DNA interactions and biocidal activity of metal complexes of benzothiazole Schiff bases: synthesis, characterization and validation

“…50 The extent of the hypochromism commonly parallels with the intercalative binding strength. 51 The electronic absorption spectra of 1 (400 nm), 2 (401 nm), 3 (403 nm), 4 (377 nm), 5 (391 nm) and 6 (390 nm) show intense absorption bands. In order to compare the DNA binding propensity of the compounds quantitatively, the intrinsic binding constant K b of the complexes with CT-DNA was determined according to the eq.…”

Anti-proliferative activity, molecular modeling studies and interaction with calf thymus DNA of novel ciprofloxacin analogues

“…[29][30][31][32] The intrinsic binding constant (Kb) was found out from following equation. 33 [DNA] /|ε a − ε…”