Efficient synthesis of ruthenium complexes of the type (R-bpy)2RuCl2 and [(R-bpy)2Ru(L–L)]Cl2 by microwave-activated reactions (R: H, Me, tert-But) (L–L: substituted bibenzimidazoles, bipyrimidine, and phenanthroline)

Complexes of the type (R-bpy)2RuCl2 (R: H, Me, tert-but) were synthesised by microwave-activated reactions of [Ru(cod)Cl2]n with substituted 2,2′-bipyridines in dimethylformamide as the solvent. The complexes were isolated in high yields and high purity from the reaction mixture. Microwave-assisted or thermal reaction of the (R-bpy)2RuCl2 solutions with substituted bibenzimidazoles, 1,10 phenanthroline or bipyrimidine in dmf/water mixtures resulted in the formation of mixed ligand complexes of the type [(R-bpy)2Ru(L–L)]Cl2. The complexes were characterised by NMR spectroscopy and MS. Furthermore, their photochemical and electrochemical properties were investigated and the solid state structure of (4-tert-butyl-bpy)2RuCl2 (3), [(4-tert-butyl-bpy)2Ru(tetramethylbibenzimidazole)](PF6)2 (4), and [(4-tert-butyl-bpy)2Ru(bipyrimidine] (PF6)2 (5) was determined by X-ray diffraction analysis of single crystals.