Tetrameric Self-Assembly of a Cu(II) Complex Containing Schiff-Base Ligand and Its Unusually High Catecholase-like Activity

摘要

We report a new tetrameric supramolecular Cu(II) complex (Qu4L4 = tetrakis(N,N-bis(salicylidene)-2,2-ethyl-enedianiline)Copper(II)) with a Schiff-base ligand (H2L = N,N-bis (salicylaldimine)-1,2-ethylenediamine) containing two N,0-bidentate chelate groups. Though the copper sites of Cu4L4 are non-coupled, the complex exhibits a unsually high catecholase-like activity (k_(cat) = 935 h~(-1)) when the Cu4L4 solution is treated with 3,5-di-tert-butylcatechol (3,5-DTBC) at basic condition in the presence of air. Combined information obtained from UV-VIS and EPR measurements could lead the suggestion of the reaction pathway in which the substrate may bind to Cu(II) ions by anti-anti didentate bridging mode.