Synthesis, Staructure and Redox Properties of Cu(II) Chelate Complexes on the Basis of 2‐(Hydroxyphenyl)‐1H‐benzo[d]imidazol‐1‐yl Phenol Ligands. Issue 21 (13th May 2021)

• Record Type: Journal Article
• Authors: Ivakhnenko, Eugeny P.; Knyazev, Pavel A.; Vitkovskaya, Yulia G.; Popov, Leonid D.; Lyssenko, Konstantin A.; Demidov, Oleg P.; Starikov, Andrey G.; Borodkin, Gennady S.; Minkin, Vladimir I.
• Is Part Of: European journal of inorganic chemistry. Issue 21(2021)
• Page Start: 2055
• Page End: 2062
• Publication Date: 2021-05-13
• Subjects: Cu(II) complexes -- Phenoxyl radicals -- Biradicals -- Triradicals -- DFT calculations; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.202100184
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: A series of 2‐(hydroxyphenyl)‐1H‐benzo[d]imidazols bearing readily oxidizable 2, 6‐di‐tert‐butyl‐phenol substituents and bis‐chelate Cu(II) complexes based on these ligands were synthesized. The structure of the compounds was characterized by NMR, IR, mass spectroscopy and X‐ray crystallographic analysis and redox behavior explored using ESR spectra and cyclic voltammetry. Under oxidation with PbO2 in toluene solution both the ligands and Cu(II) complexes form stable phenoxyl‐type radicals. As shown by ESR measurements and DFT calculations, no exchange interaction exists between unpaired electrons located on metal and oxygen centers in the biradical Cu (II) complexes. The ligands and complexes reveal antioxidant radical scavenging activity measured spectrophotometrically and using ESR and DPPH‐tests. Abstract : A series of 2‐hydroxyphenyl‐1H‐benzo[d]imidazols bearing readily oxidizable 2, 6‐di‐ tert ‐butyl‐phenol substituents and bis‐chelate Cu(II) complexes based on these ligands were synthesized. Under oxidation both the ligands and Cu(II) complexes form stable phenoxyl‐type radicals. As shown, no exchange interaction exists between unpaired electrons located on metal and oxygen centers in the Cu(II) complexes.