J. Lai, Cheang Wei Chan, C. Ng
Feb 15, 2016
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Influential Citations
8
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract The hydrated and anhydrous forms of the copper(II) complex of 3-methylpicolinic acid, monomeric [Cu(3Me-pic) 2 (H 2 O)]·H 2 O 1 and polymeric [Cu(3Me-pic) 2 ] n 2 , were synthesized and characterized by FTIR, UV–visible spectroscopy, conductivity measurement, magnetic susceptibility determination, electron paramagnetic resonance (EPR) and light scattering. Crystal structure analysis of 2 shows that it has a doubly-bridged polymeric structure, involving diagonally stacked Cu(3Me-pic) 2 units which are linked via carbonyl oxygen atoms of the 3Me-pic moieties. Analysis of EPR spectra at 133 K and 293 K suggests isotropic intermolecular spin interaction only in 2 . Complex 2 dissolved in DMF and DMSO solvents to yield nano-size particles. Solution studies show aqueous solutions of 1 and 2 contain the same neutral Cu(3Me-pic) 2 species, which generates less hydroxyl radicals from the reaction with hydrogen peroxide than their precursor CuCl 2 . The Cu(3Me-pic) 2 species exhibit more selective inhibition of the β2 site of the 20S proteasome, among the three proteolytic sites.