Syntheses, Luminescent Properties And DNA-Binding Of Polypyridyl Ruthenium (Ⅱ) Complexes

In resent years, the interaction of polypyridyl ruthenium(II) complexes with DNA has been an active subject in international bioinorganic chemistry field. The shape and substitutes of polypyridyl ligands take great effects on DNA-bindings properties of the complexes. In this thesis, a series of novel polypyridyl ligands with multi coordination sites and their ruthenium(II) complexes were designed and synthesized, the luminescent properties and DNA-binding properties of these complexes were studied. The main work was as following:1. Syntheses and characteration of polypyridyl ligands with multi coordination sitesA series of polypyridyl ligands containing multi coordination sites with different substitutes involing ODCIP(3, 4-dichloro-imidazo[4, 5-f][1, 10]phenanthroline), ODBIP(3, 4- dibromo-imidazo[4, 5-f][1, 10]-phenanthroline), MDBIP(3, 5-dibromo-imidazo[4, 5-f][1, 10] -phenanthroline), and MDNIP(2, 4-dinitro-imidazo[4, 5-f][1, 10]-phenanthroline) were synthesized and characterized by elemental analyses,IR,NMR and FAB-MS.2. Syntheses, DNA-Binding and luminescent properties of monometallic polypyridyl ruthenium(II) complexesThe different monometallic polypyridyl ruthenium(II) complexes [Ru(L₁)₂L₂]²⁺(L₁=bpy, phen; L₂=ODCIP, ODBIP, MDBIP, MDNIP) were synthesized and characterized by elemental analyses,IR,FAB-MS and NMR. The interactions of these complexes with DNA have been investigated by electronic absorption, steady-state emission intensity, steady-state emission quenching and viscosity experiments. The effects of the ancillary ligands, the intercalative ligands, and the substitutes of the ligands on the DNA-binding of these complexes have been investigated.3. The formation, DNA-binding and luminescent properties of heterobimetallic polypyridyl ruthenium(II) complexes The formation of heterobimetallic polypyridyl ruthenium(II) complexes by coordination of monometallic ruthenium(II) polypyridyl complexes with different transition metal ions were studied. The change on the luminescent properties and DNA-binding were also investigated. The results suggested that the monometallic ruthenium(II) polypyridyl complexes could coordinate with the different transition metal ions to form the heterobimetallic complexes [(L₁)₂M₁(L₂)M₂]⁴⁺( M₁=Ru²⁺;M₂=Ni²⁺,Co²⁺,Cu²⁺,Zn²⁺; L₁=bpy,phen; L₂=ODCIP,ODBIP,MDBIP,MDNIP) in the presence or absence of DNA, and the luminescence of complexes exhibited obvious changes. The complexes could change between the mono and heterobimetallic complexes by change of [M₂]/[M₁]. The complexes could be potential canditates of cycling molecular light switches by controling their different luminescence.4. Syntheses, DNA-binding and luminescent properties of homobimetallic polypyridyl ruthenium(II) complexesHomobimetallic complexes [(bpy)₂Ru(tpphz)Ru(bpy)₂]⁴⁺,[(phen)₂Ru(tpphz)Ru(phen)₂]⁴⁺ (tpphz = tetrapyrido[3,2-a:2',3'-c:3'',2''-h:2''',3'''-j]phenazine) were synthesized and characterized by elemental analyses,IR,FAB-MS and NMR. The luminescent properties and the interactions of these complexes with DNA have been investigated by electronic absorption, steady-state emission intensity, steady-state emission quenching and viscosity experiments. The results suggested that homobimetallic ruthenium(II) complexes bound to DNA by partial intercalation, the binding affinity with DNA were weaker than the corresponding monometallic ruthenium(II) complexes [Ru(bpy)₂tpphz]²⁺ and [Ru (phen)₂tpphz]²⁺.