Synthesis, crystal structures, electrochemically studies and antibacterial properties of three new mono-nuclear and one very rare bi-nuclear cobalt(III) Schiff base complexes

New complexes of Ni(II) and Cu(II) with tridentate ONO Schiff base ligand: synthesis, crystal structures, electrochemical and theoretical investigation

“…The IR spectra of these ligands further showed a strong band at 1627 cm −1 attributable to υ(C = N). This band, in the FT-IR spectra of the complexes, shifted to lower frequencies almost between 10 and 30 cm −1 probably indicating the involvement of nitrogen in coordination to the metal ions [23].…”

“…Considering the remarkable importance of Schiff base complexes and so as to continue our previous work [22][23][24][25], we found it worthwhile to synthesize and characterize new complexes of Ni(II) and Cu(II) with 1-methyl-imidazole and a tridentate Schiff base ligand, obtained by the condensation of 2-aminophenol with 5-bromo-2-hydroxybenzaldehyde (Scheme 1). In addition, a theoretical study was conducted on the structure and nature of the metal-ligand bond in complexes at the BP86/ TZ2P(ZORA)//BP86/def2-SVP level of theory.…”

Effective DNA binding and cleaving tendencies of malonic acid coupled transition metal complexes

“…The polarity of the metal ion decreases after the chelation owing to the overlap of the planar ligand orbitals which causes increase in the delocalization of p-electrons over the whole chelate ring. This consecutively enhances the penetration of the complexes into lipid membranes thereby blocking the metal binding sites in the enzymes of the microorganisms, resulting in the desired activity [44]. The order of the activity is given as follows: 5 > 1>6 > 2>7 > 3>8 > 4.…”

Characterization, crystal structures, electrochemical and antibacterial studies of four new binuclear cobalt(III) complexes derived from o-aminobenzyl alcohol

“…The other bands at around 420 nm were assigned to the charge transfer transitions of the complexes. Also, in the cobalt(III) complexes, the d-d transitions were observed in the 502-550 range [21][22][23][24].The d-d bands of complexes were observed small intensities because of small molar absorption coefficient of these forbidden transitions.…”

“…The coordination geometry of these complexes depends upon various factors including the size and electronic configuration of the central metal ions, non-bonding interactions between atoms in different ligand arms and the inherent rigidity due to the presence of aromatic rings. In the recent years, we have prepared a series of cobalt(III) complexes with Schiff base ligands, and we characterized them by their spectroscopic, structural and cyclic voltammetric properties [21][22][23][24]. In the present study, we report the synthesis of four new binuclear cobalt(III) complexes derived from two tridentate Schiff base ligands in the presence of pyridine or 4-methylpyridine (Scheme 1).…”