Heteroleptic ruthenium(II) polypyridine complexes with a series of substituted 2,2′-bipyridine ligands

Five substituted-2,2'-bipyridine ligands L, (4-(p-methylphenyl)-6-phenyl-2,2'-bipyridine (L1), 4-(p-bromophenyl)-6-(p-bromophenyl)-2,2'-bipyridine (L2), 4-(pbromophenyl)-6-phenyl-2,2'-bipyridine (L3), 4-phenyl-6-(p-bromophenyl)-2,2'-bipyridine (L4), and 4-(p-fluorophenyl)-6-(p-fluorophenyl)-2,2'-bipyridine (L5) were synthesized by stepwise formation. Reaction of cis-[RuCl2(bpy)(2)]center dot 2H(2)O or cis-[RuCl2 (phen)(2)]center dot 2H(2)O and the substituted-2,2'-bipyridine ligands in the presence of KPF6 afforded the corresponding cationic polypyridine-ruthenium complexes of the type [(bpy)(2)Ru(L)](PF6)(2) (bpy = 2,2'-bipyridine, 1-5) or [(phen)(2)Ru(L)](PF6)(2) (phen = 1,10-phenanthroline, 6-10), respectively. All complexes have been spectroscopically characterized by UV-vis, luminescence, and electrogenerated chemiluminescence. The structures of 1 center dot CH3COCH3, 3 center dot CH3COCH3, 5 center dot 2CH(3)COCH(3), 6, 8, 9, and 10 have been determined by single-crystal X-ray diffraction. [GRAPHICS] .