Unusual EPR Spectra with Inverse Axial g values of Chlorosalicylate–Cu(II)–2,6-Pyridinedimethanol Complex in Frozen Water–Methanol Solution

Husáriková, L.; Repická, Zuzana; Moncóľ, Ján; Valigura, Dušan; Valko, Marián; Mazúr, Milan

doi:10.1007/s00723-012-0431-9

Cited by 13 publications

(5 citation statements)

References 43 publications

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“…Thus, the abovementioned results suggest that the Cu(II) complex has a tetragonally distorted octahedral geometry. [ 25 ] In axial symmetry, the exchange interaction parameter (G) can be determined as G = (g‖ − 2)/(g⊥ − 2). Generally, if G is larger than 4, the exchange interaction between Cu centers in the solid state is negligible; however, when G is smaller than 4, a significant exchange interaction exists between Cu(II) ions.…”

Section: Resultsmentioning

confidence: 99%

Characterization, theoretical investigation, and biological applications of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of a triazene ligand containing a benzothiazole ring

Alamri

Al-Jahdali

Al‐Radadi

et al. 2021

Applied Organom Chemis

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Herein, Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of a previously synthesized triazene ligand, namely, (E)-2-(3-(4-nitrophenyl)triaz-1-en-1-yl)benzo [d]thiazole (L), were prepared. The metal:ligand ratio of complexes was determined by molar ratio method, and complexes were synthesized based on the result ratio (1:2 for Co(II), Ni(II), and Zn(II) complexes, and (1:1) for Cu(II) and Mn(II)). The complexes were characterized by infrared (IR) and electron paramagnetic resonance (EPR) spectroscopies, magnetic moment, and/or molar conductance measurements. IR spectra suggested the existence of bidentate binding through the nitrogen atom of the thiazole ring and nitrogen atom of the triazene linkage. Molar conductivities indicated the nonelectrolytic nature of all the complexes. Magnetic moment and EPR of the complexes confirmed their octahedral geometries. Thermal studies were conducted to confirm the structures and analyze the thermal stabilities of the complexes. Activation thermodynamic parameters were determined using the Coats-Redfern and Horowitz-Metzger methods. The calf thymus DNA binding activity was investigated by absorption titration experiments and viscosity measurements, and intrinsic binding constants of complexes range from 4.00 Â 10 5 to 5.00 Â 10 5 M À1 . Cytotoxic activities were examined against MCF-7 and HCT-116 cell lines. Although all the complexes exhibited reasonable cytotoxic effects, their cytotoxic activities were in the following order: Zn(II) > Cu(II) > Mn(II) > Co(II) > Ni(II). Zn(II) complex showed the highest activity with IC 50 values are 2.87 and 1.94 μg ml À1 against MCF-7 and HCT-116, respectively. Molecular docking was used to assess the binding affinities of these complexes to colon cancer (3ig7) and breast cancer (1hk7) proteins.Zn(II) complex showed the best docking scores compared with the ligand and other tested complexes. Results of molecular docking well correlated with those of the cytotoxicity experiments.

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Section: Resultsmentioning

confidence: 99%

Characterization, theoretical investigation, and biological applications of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of a triazene ligand containing a benzothiazole ring

Alamri

Al-Jahdali

Al‐Radadi

et al. 2021

Applied Organom Chemis

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“…EPR parameters obtained for our complexes match reasonably well with other reported mononuclear Cu(II) complexes in square-pyramidal geometry. 42,51 These type of EPR spectra commonly termed as 'usual' axial signal 52 indicate that these three complexes have mononuclear Cu(II) center in a square pyramidal geometry or elongated octahedral geometry with d x 2 -y 2 ground state. 28,[53][54][55][56] The EPR data in frozen solution suggest that the crystal structure obtained for complex 4 is retained in solution.…”

Section: Optical Spectroscopymentioning

confidence: 99%

Mononuclear nickel (II) and copper (II) coordination complexes supported by bispicen ligand derivatives: Experimental and computational studies

Singh¹,

Niklas²,

Poluektov³

et al. 2017

Inorganica Chimica Acta

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“…A unique feature of EPR is its ability to elucidate the directly bonded magnetically active atoms to a paramagnetic center of the complex and to describe the stereochemistry around a metal ion. This is substantiated by the resolution of superhyperfine (shf) structure in EPR spectra due to the magnetically active nuclei of donor atoms in metal complexes which provide valuable information about the nature of metal-ligand bonding [19].…”

Section: Introductionmentioning

confidence: 99%

EPR Spectroscopy of a Clinically Active (1:2) Copper(II)-Histidine Complex Used in the Treatment of Menkes Disease: A Fourier Transform Analysis of a Fluid CW-EPR Spectrum

et al. 2014

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Redox active transition metal ions (e.g., iron and copper) have been implicated in the etiology of many oxidative stress-related diseases including also neurodegenerative disorders. Unbound copper can catalyze formation of reactive oxygen species (hydroxyl radicals) via Fenton reaction/Haber-Weiss chemistry and therefore, under physiological conditions, free copper is potentially toxic and very rarely exists inside cells. Copper(II) bound to the aminoacid L-histidine represents a species discovered in blood in the mid 60s and since then extensive research on this complex was carried out. Copper bound to L-histidine represents an exchangeable pool of copper(II) in equilibrium with the most abundant blood plasma protein, human serum albumin. The structure of this complex, in aqueous solution, has been a subject of many studies and reviews, however without convincing success. The significance of the (1:2) copper(II)-L-histidine complex at physiological pH documents its therapeutic applications in the treatment of Menkes disease and more recently in the treatment of infantile hypertrophic cardioencephalomyopathy. While recently the (1:2) Cu(II)-L-His complex has been successfully crystallized and the crystal structure was solved by X-ray diffraction, the structure of the complex in fluid solution at physiological OPEN ACCESSMolecules 2014, 19 981 pH is not satisfactorily known. The aim of this paper is to study the (1:2) Cu(II)-L-histidine complex at low temperatures by X-band and S-band EPR spectroscopy and at physiological pH at room temperature by Fourier transform CW-EPR spectroscopy.

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Unusual EPR Spectra with Inverse Axial g values of Chlorosalicylate–Cu(II)–2,6-Pyridinedimethanol Complex in Frozen Water–Methanol Solution

Cited by 13 publications

References 43 publications

Characterization, theoretical investigation, and biological applications of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of a triazene ligand containing a benzothiazole ring

Characterization, theoretical investigation, and biological applications of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes of a triazene ligand containing a benzothiazole ring

Mononuclear nickel (II) and copper (II) coordination complexes supported by bispicen ligand derivatives: Experimental and computational studies

EPR Spectroscopy of a Clinically Active (1:2) Copper(II)-Histidine Complex Used in the Treatment of Menkes Disease: A Fourier Transform Analysis of a Fluid CW-EPR Spectrum

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