Copper(II) Catecholate Complexes with Polypyridyl Ligands

• Published in: Russian journal of inorganic chemistry 2023-09, Vol.68 (9), p.1133-1142
• Main Authors: Trofimova, O. Yu, Pashanova, K. I., Ershova, I. V., Arseniev, M. V., Yakushev, I. A., Dorovatovsky, P. V., Aisin, R. R., Piskunov, A. V.
• Format: Article
• Language: English
• Subjects: Anions; Benzoquinone; Charge transfer; Chemical synthesis; Chemistry; Chemistry and Materials Science; Chromophores; Coordination Compounds; Copper; Electronic structure; Inorganic Chemistry; Ligands; Quantum chemistry; Quinoxalines
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023623601344

Copper(II) catecholate complexes based on 3,6-di- tert -butyl- o -benzoquinone with N-donor ligands of the phenanthroline series have been synthesized: (3,6-Cat)Cu(Phen) ( I ), (3,6-Cat)Cu(DPQ) ( II ), and (3,6-Cat)Cu(DPPZ) ( III ), where 3,6-Cat is the 3,6-di- tert -butyl- o -benzoquinone dianion, Phen is phenanthroline, DPQ is dipyrido[3,2- d :2',3'- f ]quinoxaline, and DPPZ is dipyrido[3,2- a :2',3'- c ]phenazine. The synthesized copper(II) complexes demonstrate intramolecular ligand-to-ligand charge transfer responsible for their intense violet color. The electronic structure of the synthesized chromophores was studied by electronic spectroscopy, cyclic voltammetry, and quantum-chemical calculations. The molecular and crystal structures of the synthesized compounds were determined by X-ray diffraction analysis (CIF files CCDC 2 250 975 ( I ⋅THF), 2 250 976 ([( II ⋅THF)( II )]⋅3THF), 2250977 ( II )).