| With the development of science and technology,biology has become more and more important.Because DNA is a main carrier of life information,in recent years it has inspired great interest across of wide fields of scientific enthusiasm among scientists.The coordination complexes,synthesized by transition metals and polypyridines as raw materials,are more and more important because of their various structures and extensive uses.The use foreground of these complexes will be extensive in the field of molecular discernment,nucleic acid probe,anti-tumour medicine,molecular catalysis and self-assemble etc.So,preparing new polypyridine complexes and studying their properties and DNA binding are of important significance to the development of new nucleic acid probe and sensitive material used in fiber DNA biosensor.This thesis presented the preparation of a novel polypyridyl ligand and its ruthenium complex,and the interaction between this polypyridine complex with calf thymus DNA.The work of this paper includes mainly two aspects as followed:(1)The preparation of a polypyridyl ligand and its ruthenium complex:a novel polypyridyl ligand——1,10-phenanthroline-5,6-diphenylhydrazone(abbreviated as PDPH)was synthesized,using phenanthroline and phenylhydrazine as initial materials through 1,10-phenanthroline-5,6-dione intermediate.Using PDPH as ligand,a new complex[Ru(phen)2PDPH](ClO4)2·H2O,where phen denotes 1,10-phenanthroline,had also been synthesized.They were characterized by means of elemental analysis,IR and electronic absorption spectra.The effect factors of the reactions had been analyzed,furthermore,the luminescence spectra of PDPH and [Ru(phen)2PDPH](ClO4)2·H2O were studied,The results indicated that both of them exhibited strong fluorescence property.Excitation wavelength and emission wavelength of[Ru(phen)2PDPH](ClO4)2·H2O was 477 nm and 628 nm respectively.(2)The interaction study between the polypyridine complex with calf thymus DNA:several methods involving electronic absorption,emission and emission quenching,DNA competitive binding with ethidium bromid and viscosity measurement had been used to study the interaction between this polypyridine complex with calf thymus DNA,and the study results were as follows:on the incremental addition of DNA,the ultraviolet and visible absorption bands of [Ru(phen)2PDPH](ClO4)2·H2O decreased in intensity significantly,while the fluorescence intensity of the complex were enhanced evidently.The fluorescence intensity of the EB-DNA system weakened with increasing concentration of [Ru(phen)2PDPH](ClO4)2·H2O,it was a static quenching process.The fluorescence intensity of[Ru(phen)2PDPH](ClO4)2·H2O was quenched strongly by[Fe(CN)6]4-on absence of DNA,and the quenching curve met the Stern-Volmer equation.The fluorescence quenching of this complex by[Fe(CN)6]4-was decreased greatly when DNA was present,DNA could prevent this compex being quenched strongly by [Fe(CN)6]4-.The relative viscosity of DNA was increased and the denaturation temperature of DNA decreased after this complex was added.The results showed that[Ru(phen)2PDPH](ClO4)2·H2O binded significantly with DNA by interaction of PDPH into the DNA base pairs.The bind constant of the compex and DNA was determined to be(1.58±0.3)x105L/mol.[Ru(phen)2PDPH](ClO4)2·H2O interacted with DNA strongly,and the interaction could be detected by fluorescence spectra,so it provided a good fluorescence probe for the determination of DNA,and could be used as a potential sensitive material of optic DNA biosensor based on determinating the change of optical parameter.
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