Nickel(II) complexes of N2S2 donor set ligand and halide/pseudohalides: Synthesis, crystal structure, DNA and bovine/human serum albumin interaction

Abstract

A series of neutral hexacoordinated nickel(II) complexes of formula [NiII(L)X2] (where L = 3,4-bis(2-pyridylmethylthio)toluene with tetradentate N2S2 donor set and X = chloride (1), azide (2), cyanate (3) and isothiocyanate anion (4)) have been synthesized and isolated in pure form. The complexes were characterized by physicochemical and spectroscopic methods along with detailed structural characterization of 1,2 and 3 by single crystal X-ray diffraction analyses. The structural study showed that the nickel(II) ion has a distorted octahedral geometry being chelated by the tetradentate N2S2 ligand and bound to cis- located choride or pseudohalide anions. In dimethylformamide solution the complexes showed quasi-reversible NiII/NiIII redox\ud couples in cyclic voltammograms with E1/2 values of +0.723, +0.749, +0.768 and +0.868 V for 1, 2, 3 and 4, respectively. The study of interaction of the complexes with calf thymus DNA, bovine serum albumin (BSA) and human serum albumin (HSA) using spectroscopic and physicochemical tools clearly indicates that the complexes interact with DNA via groove binding mode

Supramolecular interaction of transition metal complexes with albumins and DNA: Spectroscopic methods of estimation of binding parameters

“…The major attention in the case of metal complexes binding with proteins is paid to the therapeutic properties, and only in some cases the binding parameters were studied which, if necessary, were improved by changing temperature [8,23,[33][34][35][36][37][38][39] or selecting organic and inorganic coligands (mostly 1,10-phenantholine and bipyridyl) which bind with a complexing metal together with a drug molecule. [8,24,36,37,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54] The complexes under study are mainly biligand complexes containing a drug ligand and coligand. The Figure 3 shows the distribution of the studing from the viewpoint of metals studied.…”

“…Studying the nature of the complex-DNA binding, the absorption spectra are recorded maintaining a constant DNA concentration and increasing the amount of metal complex. [24] The growth or widening of absorption band indicates the complex-DNA binding. The primary methods of calculating the constants are given below.…”

“…The binding constant is calculated from the slope / intersection point relation. [24,138,141] The example of such a plot is shown in Figure 15. Similar measurements of the binding constant can be also carried out for other albumins.…”

“…[23] It is well known that some coordination compounds may inhibit cancer cell multiplication due to binding and damage to DNA. [24] It is obvious that such research should be aimed at the search for not only compounds with a specified functionality but those possessing physicochemical parameters providing a definite rate and stability of binding of the complexes with the components of living systems. As the result, at present, a significant database has already been accumulated on the supramolecular binding of metal complexes, performing the function of drugs, with serum albumins and DNA.…”

Synthesis, crystal structure, thermal and theoretical studies of bis(N-ethyl-N-phenyldithiocarbamato) Ni(II) and (N-ethyl-N-phenyldithiocarbamato) (isothiocyanato) (triphenylphosphine) Ni(II)

“…18,19 Furthermore, a series of neutral nickel(II) complexes have been used to study the interaction of complexes with calf thymus DNA, bovine serum albumin (BSA) and human serum albumin (HSA). 20 Nickel(II) complexes containing ONS donor ligands have been applied as catalyst towards C-C cross-coupling reactions. 21 Different nickel complexes with nuclease activity have been reported in literature.…”