Cu(II), Ni(II), and Zn(II) Complexes of Salan-Type Ligand Containing Ester Groups: Synthesis, Characterization, Electrochemical Properties, andIn VitroBiological Activities

Abstract

A salen ligand on reduction and N-alkylation affords a novel [N2O2] chelating ligand containing ester groups [L = diethyl-2,2′-(propane-1,3-diylbis((2-hydroxy-3-methoxy benzyl)azanediyl))diacetate]. The purity of the ligand was confirmed by NMR and HPLC chromatograms. Its Cu(II), Ni(II), and Zn(II) complexes were synthesized and characterized by a combination of elemental analysis, IR, NMR, UV-Vis, and mass spectral data, and thermogravimetric analysis (TG/DTA). The magnetic moments, UV-Vis, and EPR spectral studies support square planar geometry around the Cu(II) and Ni(II) ions. A tetrahedral geometry is observed in four-coordinate zinc with bulky N-alkylated salan ligand. The redox properties of the copper complex were examined in DMSO by cyclic voltammetry. The voltammograms show quasireversible process. The interaction of metal complexes with CT DNA was investigated by UV-Vis absorption titration, ethidium bromide displacement assay, cyclic voltammetry methods, and agarose gel electrophoresis. The apparent binding constant values suggest moderate intercalative binding modes between the complexes and DNA. The in vitro antioxidant and antimicrobial potentials of the synthesized compounds were also determined.

Synthesis, Characterization, Anticancer, and Antioxidant Studies of Ru(III) Complexes of Monobasic Tridentate Schiff Bases

“…The presence of coordinated water gave a broad band that appeared in the regions 3416–3436 and 813–851 cm −1 ; this can be due to ν (O-H) stretching and ν (O-H) rocking vibrations, respectively, which further confirms the presence of nonligand assignable to the rocking mode of water [28, 34]. New weak nonligand bands that are not found in the DAE, HME, MBE, and DEE ligands appeared in the ranges 475–548 cm −1 and 436–475 cm −1 in the complexes spectra attributed to ν (Ru-N) and ν (Ru-O) vibrations, respectively [35, 36]. A band ranging from 311–346 cm −1 appeared in the spectra of the Ru(III)-Schiff base complexes indicating the presence of two chloride ions in trans position around ruthenium centre [37–40].…”

Three pairs of enantiomers bearing mitochondria‐targeted TPP+ groups as potential anti‐cancer agents

“…The intrinsic binding constants K b reflecting the binding strength of the complexes and CT‐DNA were calculated, the magnitude of the K b values of the six complexes was between 10 5 and 10 6 , and more details are shown in Table S3. These values are comparable to the observed value for some complexes like [Zn(5‐CH 2 PPh 3 –3,4‐salpyr)](ClO 4 ) 2 (3.33 × 10 3 ); [Zn(5‐CH 2 PPh 3 –3,4‐salpyr)](ClO 4 ) 2 (2.22 × 10 3 ); Cu L 1 (10 × 10 4 ); Ni L 1 (5 × 10 4 ); Zn L 1 (4 × 10 4 ) [ L 1 = diethyl‐2,2‐(propane‐1,3‐diylbis((2‐hydroxy‐3‐methoxy‐ benzyl)azanediyl))diacetate] . The achieved values indicate that 1–6 are moderately bound to CT‐DNA, which is likely to reveal the efficiency of DNA binding activity were strengthened, may due to the intercalation of benzene ring from the diamine with the base pairs of DNA.…”

Synthesis, Characterization, and Cytotoxic Activities of a Schiff Base Ligand and Its Binuclear Copper(II) and Manganese(III) Complexes

“…π→π * transition of the aromatic rings. The azomethine π→π * transition band appears at 332 nm(37). The electronic spectra of the metal complexes have a similar profile.…”