Mononuclear copper(II) saccharinate (sac) complex containing ethylnicotinate (enc), [Cu(enc)(2)(sac)(2)(H(2)O)].1.4H(2)O has been synthesized and characterized by spectroscopic (IR, UV-vis, EPR), X-ray diffraction technique and electrochemical methods. It crystallizes in the tetragonal crystal systems with space group I4(1)cd and Z=8. The copper(II) ion presents a CuN(4)O distorted square pyramidal coordination. Based on EPR and optical absorption studies, spin-Hamiltonian and bonding parameters have been calculated. The g-values, calculated for title complex in polycrystalline state at 298 K and in frozen DMF (110K), indicate the presence of the unpaired electron in the d(x)(2)-(y)(2) orbital. The evaluated metal-ligand bonding parameters showed strong in-plane sigma and in-plane pi-bonding. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed. The cyclic voltammogram of the title complex investigated in DMF (dimethylformamide) solution exhibits only metal centred electroactivity in the potential range +/-1.25 V vs. Ag/AgCl reference electrode.
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http://dx.doi.org/10.1016/j.saa.2008.06.046 | DOI Listing |
ChemMedChem
December 2024
University of Puerto Rico Rio Piedras: Universidad de Puerto Rico Recinto de Rio Piedras, Chemistry, 17 University Avenue, 00925, San Juan, UNITED STATES OF AMERICA.
Deferasirox (Def), an orally administered iron-chelating drug, has drawn significant interest in repurposing for anticancer application due to the elevated Fe demand by cancer cells. But there are also concerns about its severe off target health effects. Herein Cu(II) binding is studied as a potential off target interaction.
View Article and Find Full Text PDFDalton Trans
December 2024
Department of Chemistry, College of Humanities and Sciences, Nihon University, 3-25-40 Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan.
The spin coherence phenomena of a system consisting of a mononuclear 3d transition metal = 1/2 centre embedded in a polyoxometalate with low nuclear-spin abundance, [(-CH)N]H[SiWOCuZn], have been revealed for the first time. Variable-temperature Hahn-echo experiments using the pulsed electron spin resonance technique showed that its coherence lifetime remains at the submicrosecond level even above 100 K.
View Article and Find Full Text PDFBioorg Chem
November 2024
The Laboratory of Respiratory Disease, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, China; Key Laboratory of Basic Research on Respiratory Diseases, Guangxi Health Commission, Guilin, Guangxi, China. Electronic address:
Dalton Trans
October 2024
Department of Chemistry, Graduate School of Science, Osaka University, Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
-Monosubstituted ethylenediamine derivatives with three methylene-tethered aromatic groups ((ArCH)NCHCHN(R)CHAr (R-ArArAr), where Ar = 2-pyridyl, 2-quinolyl, 1- and 3-isoquinolyl and 2-quinoxalyl; R = methyl, benzyl and phenyl) were utilized as pentadentate ligands for copper(II) complexation. Fifteen mononuclear copper(II) complexes were synthesized and exhibit differences in cyclic voltammetry, absorption spectroscopy and solid state geometries, depending on the aromatic group (Ar) and the substituent on the aliphatic nitrogen atom (R) of the ligand. Compared with the pyridine and isoquinoline complexes, the quinoline and quinoxaline derivatives exhibit distinct Cu(II)/Cu(I) redox potentials and d-d transition absorption wavelengths.
View Article and Find Full Text PDFJ Inorg Biochem
October 2024
Coordination and Bioinorganic Chemistry Research Laboratory, Department of Chemistry, National College (Autonomous), Tiruchirappalli 620 001, Tamil Nadu, India.
Copper metalloenzymes ascorbate oxidase (AOase), amine oxidase (AmOase), and catechol oxidase (COase) possess copper(II) sites of coordination, which are trimeric, homodimeric, and dimeric, respectively. Two newly mononuclear copper(II) complexes, namely, [Cu(L)(bpy)](ClO) (1) and [Cu(L)(phen)](ClO) (2) where HL = Schiff base, have been synthesized. UV-visible, EPR and single-crystal X-ray diffraction examinations were used to validate the geometry in solution and solid state.
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