Inorganic Chemistry, Vol.48, No.16, 7593-7603, 2009
Heteroleptic Arene Ruthenium Complexes Based on meso-Substituted Dipyrrins: Synthesis, Structure, Reactivity, and Electrochemical Studies
First examples of heteroleptic arene ruthenium complexes containing dipyrrin ligands with the general formulations [(eta(6)-arene)RuCl(L)] [(arene = C6H6, C10H14; L = 5-(4-cyanophenyl)-dipyrromethene. cydpm; 5-(4-nitrophenyl)-dipyrromethene, ndpm and 5-(4-benzyloxyphenyl)-dipyrromethene, bdpm] have been synthesized. The complexes [(eta(6)-C10H14)RuCl(L)] (L = ndpm and cydpm) reacted with NaN3 and NH4SCN to afford neutral mononuclear complexes [(eta(6)-C10H14)Ru(N-3)(L)] and [(eta(6)-C10H14)Ru(SCN)(L)]. Their reactions with EPh3 (E = P, As) and exobidentate ditopic P-P and N-N donor ligands, namely, bis-(diphenylphosphino)methane (dppm) and 4,4'-bipyridine (bpy) in the presence of AgSO3CF3 afforded cationic mono- and binuclear complexes [(eta(6)-C-10-H-14)Ru(L)(EPh3)]SO3CF3, [{(eta(6)-C10H14)Ru(L)}(2)(mu-dppm)]SO3CF3)(2), and [{(eta(6)-C10H14)Ru(L)}(2)(mu-bpy)](SO3-CF3)(2), respectively. The reaction products have been characterized by analytical and spectral studies. Molecular structures of the representative complexes [(eta(6)-C10H14)RuCl(cydpm)], [(eta(6)-C6H6)RuCl(cydpm)], [(eta(6)-C10H14)RuCl-(ndpm)], and [(eta(6)-C10H14)Ru(N-3)(ndpm)], and [(eta(6)-C10H14)Ru(PPh3)(ndpm)]SO3CF3 have been determined crystallographically. Redox behavior of the complexes has been investigated by electrochemical studies. Emission spectral studies at room temperature suggested that the complexes under study are non-emissive.