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

• Synthesis of mixed ligand copper(I) complexes.
• Characterization by elemental analyses, IR, NMR and single crystal X-ray analysis.
• Quasireversible redox behavior is accounted for all complexes.
• Ethynyl functionality shows marked effect on emission spectra of the complexes.

Some copper(I) complexes with imonopyridine ligands [Cu(L1)(PPh3)2]X (X = Cl (1a), ClO4 (2a), BF4 (3a), PF6 (4a)) and [Cu(L2)(PPh3)2]X (X = Cl (1b), ClO4 (2b), BF4 (3b), PF6 (4b)) [Where L1 = N-(2-pyridylmethylene)-4-(bromo)aniline, L2 = N-(2-pyridylmethylene)-4-(ethynyl)aniline; PPh3 = triphenylphosphine] have been synthesized and characterized on the basis of their elemental analyses, IR, 1H NMR and 31P NMR spectral studies. The representative complexes [Cu(L1)(PPh3)2]ClO4 (2a) and [Cu(L2)(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 (CCH) functionality on iminopyridine induces pronounced red shift in absorption and emission wavelength of copper(I) complexes.

Some copper(I) complexes with imonopyridine ligands [Cu(L1)(PPh3)2]X (1a–4a) and [Cu(L2)(PPh3)2]X (1b–4b) [Where L1 = N-(2-pyridylmethylene)-4-(bromo)aniline, L2 = N-(2-pyridylmethylene)-4-(ethynyl)aniline; PPh3 = triphenylphosphine, X = Cl−, ClO4−, BF4− and PF6−] were synthesized and characterized. 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 (CCH) functionality on iminopyridine induces pronounced red shift in absorption and emission wavelength of copper(I) complexes.Figure optionsDownload as PowerPoint slide