Synthesis, spectral characterization, properties and structures of copper(I) complexes containing novel bidentate iminopyridine ligands

Four new ligands, (4-methyl-phenyl)-pyridin-2-ylmethylene-amine (A), (2,3-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (B), (2,4-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (C) and (2,5-dimethyl-phenyl)-pyridin-2-ylmethylene-amine (D), and their corresponding copper(I) complexes, [Cu(A)(2)]ClO4 (1a), [Cu(B)(2)]ClO4 (1b), [Cu(C)(2)]ClO4 (1c), [Cu(D)(2)]ClO4 (1d), [Cu(A)(PPh3)(2)]ClO4 (2a), [Cu(B)(PPh3)(2)]ClO4 (2b), [Cu(C)(PPh3)(2)]ClO4 (2c) and [Cu(D)(PPh3)(2)]ClO4 (2d), have been synthesized and characterized by CHN analyses, H-1 and C-13 NMR, IR and UV-Vis spectroscopy. The crystal structures of [Cu(B)(2)]ClO4 (1b), [Cu(C)(2)]ClO4 (1c) and [Cu(A)(PPh3)(2)]ClO4 center dot 1/2CH(3)CN (2a) were determined from single crystal X-ray diffraction. The coordination polyhedron about the copper(I) center in the three complexes is best described as a distorted tetrahedron. A quasireversible redox behavior is observed for the complexes. (c) 2006 Elsevier Ltd. All rights reserved.