New symmetrical dinucleating ligand based assembly of bridged dicopper(II) and dizinc(II) centers: Synthesis, structure, spectroscopy, magnetic properties and glycoside hydrolysis

Three dinuclear copper(II) and zinc(II) complexes [Li(H2O)3(CH3OH)]4[Cu2Br4][Cu2(cpdp)(μ-O2CCH3)]4(OH)2 (1), [Cu(H2O)4][Cu2(cpdp)(μ-O2CC6H5)]2Cl2·5H2O (2) and [Zn2(cpdp)(μ-O2CCH3)] (3) of a new symmetrical dinucleating ligand, H3cpdp have been synthesized and characterized. Variable-temperature (2-300 K) magnetic susceptibility measurements reveal the presence of antiferromagnetic interactions between the two copper(II) centers in complexes 1 and 2. The complexes have been examined for glycosidase-like activity in aqueous solution at pH ∼ 10.5 by UV-Vis spectrophotometric technique using p-nitrophenyl-α-d-glucopyranoside and p-nitrophenyl-β-d-glucopyranoside as model substrates.