Photoinduced Electron Transfer in Pentaammineruthenium(II) Complexes of 1-(4-Cyanophenyl)imidazole.

A new bridging ligand, 1-(4-cyanophenyl)imidazole (CPI) has been prepared, as well as its N-methylated derivative 1-methyl-3-(4-cyanophenyl)imidazolium iodide (CPI-Me(+)I(-)). The mononuclear and binuclear complexes [(NH(3))(5)Ru-CPI-Me](3+) and [(NH(3))(5)Ru-CPI-Ru(NH(3))(5)](4+) have been obtained. Free CPI is planar, according to theoretical calculations (MMX and MNDO), and its luminescence properties suggest the occurence of a twisted internal charge transfer (TICT) state.