Synthesis, ESR, UV-Visible and reactivity studies of new bis(N-dimethoxyaniline-3,5-Bu-t(2)-salicylaldiminato)copper(II) complexes

Kasumov V. T., Koksal F.

SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, vol.98, pp.207-214, 2012 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 98
  • Publication Date: 2012
  • Doi Number: 10.1016/j.saa.2012.07.122
  • Journal Name: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.207-214
  • Keywords: Bis(N-dimethoxyphenyl-3,5-Bu-t(2)-salicylaldiminato)Cu(II) complexes, ESR, An inverse ESR spectrum, Cu(II)-phenoxyl radicals, Redox-reactivity, TRANSITION-METAL-COMPLEXES, PHENOXYL RADICAL COMPLEXES, ELECTRONIC-PROPERTIES, COPPER(II) COMPLEXES, GALACTOSE-OXIDASE, LIGANDS, REDOX, STEREOCHEMISTRY, SPECTROSCOPY, CHEMISTRY
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

Several new copper(II) complexes (4-6) with N-dimethoxyphenyl-3,5-Bu-t(2)-salicylaldimine ligands abbreviated as N-R-3,5-DTBS, where R = 2,4-dimethoxyphenyl (1), 2,5-dimethoxyphenyl (2) and 3,5-dimethoxyphenyl (3) have been prepared and their spectroscopic (IR, H-1 NMR, UV/Vis, ESR), magnetic and redox reactivity are described. The ESR spectra of frozen-solution 4-6 and solid state 4 and 5 are indicative of axially symmetric g-tensor (g(parallel to) > g(perpendicular to) > 2.03). The powder ESR spectrum of 6 is unusual for CuN2O2 type systems and exhibits "reversed" type (g(parallel to) < g(perpendicular to)) signal with a rhombic g-tensor g(3) (2.235) > g(2) (2.128) > g(1) (2.019) pattern indicative of a d(z)(2) state. Chemical oxidation of 4 and 6, as supported by ESR and UV/Vis techniques, generates new Cu(II) species and Cu(II)-phenoxyl radicals. The CV studies have shown that the complexes possess ligand-centered and copper(II)-centered quasi-reversible and irreversible responses. (C) 2012 Elsevier B.V. All rights reserved.