Heteroleptic Cu(I) complexes containing polypyridyl ligands and triphenylphosphine: Synthesis, structure, photophysical properties, DFT studies and applications in co-sensitized solar cells

The synthesis and characterization by IR and H-1 NMR spectroscopy, ESI-TOF+ mass spectrometry, cyclic voltammetry, single-crystal X-ray diffraction and thermal analysis of two novel heteroleptic Cu(I) complexes of general composition [Cu-I(L1)(PPh3)(2)]PF6 center dot 0.75CHCl(3)(1) and [Cu-I(L2)(PPh3)(2)] PF6 center dot 2.5CHCl(3)(2) PPh3 = triphenylphosphine, L1 = cis-(+/-)-2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1 H-imidazol-4-yl) pyridine and L2 = 2,4,6-tris(2-pyridyl) triazine) is reported. Both complexes show interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV-Vis and fluorescence spectroscopy, and theoretically by using TD-DFT calculations. Additionally, their performance as co-sensitizer in DSSC was evaluated. (C) 2017 Elsevier B.V. All rights reserved.