Three novel luminescent piano-stool arene ruthenium complexes of general formula [(eta(6)-arene)RuCI2(CPl)] (eta(6-)arene = benzene, 1, p-cymene, 2, and hexamethylbenzene, 3; CPI=1-(4-cyanophenyl)imdazole were prepared. The molecular structures of 2 and 3 were determined crystallographically. Reaction of 1-3 with EPh3 (E = P, As, or Sb) and N-N donor bases such as 2,2'-bipyridine and 1,10-phenanthroline afforded cationic mononuclear complexes of general formula [(eta(6)-arene)RuCI(CPI)(EPh3)](+) (eta(6)-arene = C6H6, E = P (1a), E = As (1b), E = Sb (1c); eta(6)-arene = C10H14, E = P (2a), E = As (2b), E = Sb (2c); eta(6)-arene = C6Me6, E = P (3a), E = As (3b), E = So (3c)) and [(eta(6)-arene)Ru(N-N)(CpI)](2+) (eta(6)-arene = C6H6, N-N = bipy (1d), N-N = phen (1e); eta(6)-arene = C10H14, N-N = bipy (2d), N-N = phen (2e); eta(6)-arene = C6Me6, N-N = bipy (3d), N-N = phen (3e)). Molecular structures of la and 2a were also confirmed by X-ray crystallography. Structural studies of the complexes 2, 3, la, and 2a supported coordination of CPI through the imidazole nitrogen and the presence of a pendant nitrile group. Structural data also revealed stabilization of crystal packing in the complexes 2, 3, and 2a by C-(HX)-X-... (X = CI, F) type inter- and intramolecular interactions and in complex la by pi-pi stacking. Moreover, neutral homonuclear bimetallic complexes 2f,g were prepared by using complex 2 as a metallo-ligand, where CPI acts as a bridge between two metal centers. Emission spectra of the mononuclear complexes [(eta(6)-arene)RuCl2(CPI)] and its derivatives exhibited intense luminescence when excited in the metal to ligand charge-transfer band.