文摘
The reaction of copper(II) bromide with 2,2′-dimethyl-4,4′-bithiazole (dm4bt) affords a dimer complex, [{CuBr(dm4bt)}2(µ-Br)2] (1), in CH3OH/CH3CN; and a monomer complex, [Cu(dm4bt)Br2(DMSO)] (2), in DMSO. Monomer copper(II) complex [Cu(4bt)Br2(DMSO)] (3) also resulted from the treatment of the copper salt with 4,4′-bithiazole (4bt) in DMSO. The complexes were characterized by elemental analysis, IR, UV and X-ray crystallography. The interaction of monomeric complexes 2 and 3 with calf thymus DNA (CT DNA) has been explored by using absorption, emission and thermal denaturation, where they exhibit high interaction ability with CT DNA, with intrinsic binding constants Kb of 1.58 × 105 and 1.24 × 105 M−1 at 298 K, for complexes 2 and 3, respectively. Furthermore, the intermolecular interaction between the mentioned copper complexes and bovine serum albumin (BSA) under imitated physiological conditions was investigated using UV–Vis and fluorescence. Tryptophan-quenching experiment illustrated that both complexes strongly bind BSA, with dynamic quenching constants of about 1 × 105 M−1 s−1 at 298 K, and a single class of binding site for the complexes on BSA.
