Unusual chemistry of Cu(ii) salan complexes: synthesis, characterization and superoxide dismutase activity. (25th June 2020)

• Record Type: Journal Article
• Authors: Roy, Satabdi; Banerjee, Atanu; Lima, Sudhir; Horn Jr, Adolfo; Sampaio, Raquel M. S. N.; Ribeiro, Nádia; Correia, Isabel; Avecilla, Fernando; Carvalho, M. Fernanda N. N.; Kuznetsov, Maxim L.; Pessoa, João Costa; Kaminsky, Werner; Dinda, Rupam
• Is Part Of: New journal of chemistry. Volume 44:Number 27(2020)
• Page Start: 11457
• Page End: 11470
• Publication Date: 2020-06-25
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d0nj01892a
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Cu(ii )-salan complexes: structural and spectral characterization, solvent assisted ring cleavage and correlation of superoxide dismutase activity with cyclic voltammetry data and steric effects. Abstract : The diaminobis(phenolato) "salan" ligand precursors, N, N′ -dimethyl- N, N ′-bis-(2-hydroxy-3-X-5-Y-6-Z-benzyl)-1, 2-diaminoethane {X = i Pr, Y = Cl, Z = Me (H2 L 1 ); X = OCH3, Y = allyl, Z = H (H2 L 2 )} and N, N ′-bis-(2-hydroxy-3-X-5-Y-6-Z-benzyl)-4-methylimidazolidine {X = i Pr, Y = Cl, Z = Me (H2 L 3 ); X = t Bu, Y = CH3, Z = H (H2 L 4 )} and their corresponding Cu(ii ) complexes are synthesized and characterized. [Cu(L 1 )(DMSO)] and [Cu(L 2 )] show the expected geometry and coordination behavior. However, upon coordination to the Cu(ii ) centre in the presence of CH3 OH, ring cleavage in H2 L 3 and H2 L 4 occurs. Subsequent and unexpected coordination of the in situ formed pendant acetal fragment of the new ligand, formed via ring opening, leads to the formation of the phenolato bridged dimeric Cu(ii ) complex, [Cu(L 3A )]2, and a monomeric Cu(ii ) complex [Cu(L 4A )], where an extra acetal fragment is present as a pendant group. An outline of the probable mechanism for this process is proposed. The superoxide dismutase activity of the Cu(ii ) complexes is also investigated.