Synthesis, crystal structure and conjugation properties of iminopyridine copper(I) phosphine complexes

Some copper(I) complexes with imonopyridine ligands [Cu(L-1)(PPh3)(2)]X(X = Cl (1a), ClO4 (2a), BF4 (3a), PF6 (4a)) and [Cu(L-2)(PPh3)(2)] X (X = Cl (1b), ClO4 (2b), BF4 (3b), PF6 (4b)) [Where L-1 = N-(2-pyridylmethylene)-4-( bromo) aniline, L-2 = N-(2-pyridylmethylene)-4-(ethynyl) aniline; PPh3 = triphenylphosphine] have been synthesized and characterized on the basis of their elemental analyses, IR, H-1 NMR and P-31 NMR spectral studies. The representative complexes [Cu(L-1)(PPh3)(2)] ClO4 (2a) and [Cu(L-2)(PPh3)(2)] PF6 (4b) were characterized by single crystal X-ray analysis which reveals a distorted tetrahedral geometry around each copper( I) center. Quasireversible redox behavior is accounted for all complexes corresponding to Cu(II)/Cu(I) couple. Photophysical properties of all complexes indicate that the insertion of ethynyl (C equivalent to C-H) functionality on iminopyridine induces pronounced red shift in absorption and emission wavelength of copper(I) complexes. (C) 2015 Elsevier B.V. All rights reserved.