A novel series of complexes of the formula [Ru­(4,4′-X2-bpy)2(Mebpy-CN)]­(PF6)2 (X −CH3, −OCH3, −N­(CH3)2; Mebpy-CN = 4-methyl-2,2′-bipyridine-4′-carbonitrile) have been synthesized and characterized by spectroscopic, electrochemical, and photophysical techniques. Inclusion of the electron-withdrawing substituent −CN at one bpy ligand and different electron-donor groups −X at the 4,4′-positions of the other two bpy ligands produce a fine tuning of physicochemical properties. Redox potentials, electronic absorption maxima, and emission maxima correlate well with Hammett’s σp parameters of X. Quantum mechanical calculations are consistent with experimental data. All the complexes can be anchored through the nitrile moiety of Mebpy-CN over ZnO nanowires in dye-sensitized solar cells that exhibit an improvement of light to electrical energy conversion efficiency as the electronic asymmetry increases in the series.

The Schiff base of the title has been synthesized and its crystal structure determined by single-crystal X-ray diffraction. The compound was characterized by IR, Raman, H NMR,C NMR and electronic absorption spectra. DFT calculations provide the quantum chemical basis for the observed molecular conformation. A study of intermolecular interactions of the title compound is compared with seven other closely related structures and reveals that molecules in most of the compounds are linked by a cooperative effect of strong and weak hydrogen bonds, CHπ, and ππ stacking interactions, and also lpπ contacts. Lattice energy calculations indicate that the dispersion component is the major contribution, with the coulombic term playing a significant role in the total energy. Interaction energies for molecular pairs involving NH···N bonds indicate a dominant contribution to packing stabilization coming from coulomb component. Hirshfeld surfaces and 2D-fingerprint plots allowed us to visualize different intermolecular contacts and its relative contributions to total surface in each compound. The analysis of electrostatic potential (ESP) maps correlates well with the computed energies providing evidences on the dominant electrostatic nature of NH···N and NH···O interactions.