Synthesis, characterization, spectroscopic and thermodynamic studies of charge transfer interaction of a new water-soluble cobalt(II) Schiff base complex with imidazole derivatives

Spectroscopic studies and determination of the formation constants and thermodynamic parameters for a new water-soluble Co(II) Schiff-base complex and some imidazole derivatives

“…The values of the obtained thermodynamic parameters are in reasonable agreement with the previously studied cobalamins and the complex is therefore a model for the study of the cobalamin system [35]. The values of DH f and DS f are both shifted to more negative values compared to previous report [19], confirming that the starting acceptor complex is more subjected to hydrogen bonding.…”

“…Compared to the previous studies [19,20], the acceptor property of this Schiff-base complex is altered by both steric and electronic factors. The steric factor obviously disfavors complex formation but electronic factors could favor it.…”

“…The structural and electronic details of both donors and acceptors play critical roles in CT complex formation. In continuation of recent publications on this subject [19][20][21][22][23][24][25][26], herein we report the synthesis and characterization of a new Co(II) complex of a tetradentate Schiff-base ligand and spectroscopic and thermodynamic studies of its adduct formation with imidazole (Im) and 1-methylimidazole (MeIm) in three different solutions under physiological condition (pH ¼ 7). The Schiff base is chosen to be sterically and electronically different from our previous reports to obtain better understanding about the factors affecting complex formation.…”

DNA binding and DNA cleavage studies of a water soluble cobalt(II) complex containing dinitrogen Schiff base ligand: The effect of metal on the mode of binding

“…The complex was previously synthesized after isolating the Schiff base [38]. We found that it can be prepared using in situ method by mixing 3-formyl-4 hydroxybenzyl-triphenyl phosphonium chloride, Co(II) acetate and o-phenylenediamine in higher yield.…”

“…To a vigorously stirred solution (50 mL) of 3-formyl-4 hydroxybenzyl-triphenyl phosphonium chloride (0.864 g, 2 mmol) [38] was first added Co(acetate) 2 $4H 2 O (0.496 g, 2 mmol) dissolved in water (l0 mL) and then Et 3 N (pH 7.5e8). A few minutes later, an ethanolic solution (20 mL) of o-phenylenediamine (0.108 g, 1 mmol) was added drop wise.…”