New copper(II) μ-alkoxo-μ-carboxylato double-bridged complexes as models for the active site of catechol oxidase: synthesis, spectral characterization and DFT calculations.

A series of four copper(II) μ-Alkoxo-μ-carboxylato double bridged complexes, [{Cu(L)}][(μ-OC-CO] , [{Cu(L)}(μ-OC-(CH)CO] , [{Cu(L)}(μ-OC-CH-CO] and [{Cu(L)}(μ-OC-CH-CO] (HL = 4-bromo-2-((E)-((3-(((E)-5-chloro-2-hydroxybenzylidene) amino)-2-hydroxypropyl) imino) methyl)-6-methoxyphenol and μ-dicarboxylate ions = oxalate, malonate, succinate and terephthalate) have been synthesized and characterized using several physicochemical techniques. The tridentate nature of HL is interpreted from IR spectra. The Epr spectra of these complexes are characteristic of the quintet state (S = 2) in central features and the triplet state (S = 1) of these tetranuclear complexes.