The Synthesis And Luminescent Properties Of Series Of Ruthenium Complexes Supported By Polypyridyl And Phthalazine Ligand

In this thesis, a series of ruthenium complexes supported by several new polypyridyl (L1-L5) and phthalazine ligands (L6-L9) were synthesized, characterized and their UV, luminescence, ECL, and electrochemical properties were studied.Interaction of cis-(bpy)2RuCl2·2H2O and cis-(phen)2RuCl2·2H2O with these polypyridyl ligands (L1-L5) in the presence of ammonium hexafluorophosphate NH4PF6in ethanol afforded a series of isolable ionic ruthenium complexes:[(bpy)2Ru(L1)](PF6)2(Rul, L1=4’-(4-methylphenyl)-6’-phenyl-2,2’-bipyridine)),[(bpy)2Ru(L2)](PF6)2(Ru2, L2=(4’-(4-bromophenyl)-6’-(4"-bromophenyl)-2,2’-bipyridine)),(bpy)2Ru-(L3)](PF6)2(Ru3, L3=4’-(4-bromophenyl)-6’-phenyl-2,2’-bipyridine)),[(bpy)2Ru(L4)](PF6)2(Ru4, L4=4’-phenyl-6’-(4"-bromophenyl)-2,2’-bipyridine),[(bpy)2Ru(L5)](PF6)2(Ru5, L5=4’-(4-fluorophenyl)-6’-(4"-fluorophenyl)-2,2’-bipyridine)),[(phen)2Ru(L1)](PF6)2(Ru6),[(phen)2Ru(L2)]-(PF6)2(Ru7),[(phen)2Ru(L3)](PF6)2(Ru8),[(phen)2Ru(L4)](PF6)2(Ru9),[(phen)2Ru(L5)](PF6)2(Ru10). The central ruthenium atom was surrounded with six nitrogen atoms in these complexes.Treatment of cis-(phen)2RuCl2·2H2O with phthalazine ligands (L6, L7) in ethylene glycol gave cyclometalated ruthenium(Ⅱ) complexes (phen)2Ru(L6)(Rull, L6=1-(2,6-dimethylphenol)-4-phenyl-1-phthalazinamine) and (phen)2Ru(L7)(Ru12, L7=1-(2,6-isopropylphenol)-4-phenyl-1-phthalazinamine) respectively. The central ruthenium atom was surrounded with five nitrogen atoms and onecarbon atom in these complexes.The molecular structures of some of these complexes have been characterized by single-crystal X-ray diffraction, and all the complexes have also been characterized by the UV spectrum,1H, and13C NMR spectroscopies. It is found that different substituents at different positions could change the electron-donating capacity of the polypyridyl ligands, redox properties and luminous intensity of the complexes (Rul-Ru10), especially in complex Ru2with bis-bromine as substituents. For example, the maximum wavelength of MLCT (metal-to-ligand charge-transfer) in Ru2shows blue shift, stronger luminescence compared to other related ruthenium complexes. Complexes Rull and Ru12supported by phthalazine ligands show typical and richer absorption peaks of bipyridyl ruthenium complexes in the UV spectrum. For example, the absorption peaks of Rull appearing at214,265and492nm are very similar to Ru12(220,266,495nm). The maximum wavelength of MLCT of Rull and Ru12shows red shift about40nm and the absorption spectra significantly extended. So the absorption of the long wavelength region is significantly enhanced and these complexes are hopefully to prepare efficient dye-sensitized solar cell.Electrochemical research has also been conducted on the ruthenium complexes Rul-Ru10The luminescence properties of Ru6-Ru10are better than Rul-Ru5, and meta-bromo substituted complex Ru4is the best among these complexes. The redox peaks of these complexes are similar to Ru(bpy)3(PF6)2, and oxidation property of Ru2is weaker than others. Besides, the ECL emission intensity showed that the order of luminous intensity is Ru2> Ru5> Ru3> Ru4> Rul, and it is found that bromo substituent can promote electron transfer at the electrode surface.