Synthesis And Properties Of Pyrazino[2,3-f][1,10] Phenanthroline Derivatives And Their Complexes

Pyrazino[2,3-f][1,10]phenanthroline as1,10-phenanthrline derivatives can show variousproperties with σ donor/π acceptor. Due to lower energy of larger π conjugation system, it hasbeen extensively applied as ligand of complex in both analytical and coordination chemistry.Attached by aryl substituent, pyrazino[2,3-f][1,10]phenanthroline will present morecharacteristic propertie. In the thesis, a number of pyrazino[2,3-f][1,10]phenanthroline ligandsand complexes have been synthesized and characterized. The relation of structure andproperties are also discussed.With1,10-phenanthroline and aromatic aldehydes derivatives as the starting materials,four2,3-diphenylpyrazino[2,3-f][1,10]phenanthroline as a ligand have been synthesized,2,3-diphenylpyrazino[2,3-f][1,10]phenanthroline （DPPP）,2,3-bis（4-methoxyphenyl）pyrazino[2,3-f][1,10]phenanthroline （4-MOPP）,2,3-di-p-tolylpyrazino[2,3-f][1,10]phenanthroline（4-MPP）,2,3-bis（3-methoxyphenyl）pyrazino[2,3-f][1,10]phenanthroline （3-MOPP）, havebeen obtained. It also is characterized with1H-NMR, IR and elemental analysis. With2,3-diphenylpyrazino[2,3-f][1,10]phenanthroline derivatives as the starting material, theseRu（II） complexes have also been achieved and characterized with IR,1H-NMR and elementanalysis. The photophysical results from UV-Vis and emission spectra reveal that thesubstituents can play an important role in the optical activity of the complexes. TheDNA-binding properties were investigated by means of spectraphotometrics and viscositymeasurements. The results suggest that all these four complexes can bind to CT-DNA withvarcious binding strength. Binding affinity of complexes decrease followed the sequence ofRu（bpy）²⁺₂（DPPP）, Ru（bpy）₂（4-MPP）²⁺, Ru（bpy）+2（4-MOPP）₂and Ru（bpy）₂（3-MOPP）²⁺.With1,10-phenanthroline-5,6-dione,3,4-diaminobenzoic acid and aniline derivatives asthe starting materials, three2-（dipyrido[3,2-a:2’,3’-c]phenazin-11-yl）benzo[d]zole weresynthesized,2-（dipyrido[3,2-a:2’,3’-c]phenazin-11-yl）benzo[d]oxazole（BIDPP）,2-（dipyrido-[3,2-a:2’,3’-c]phenazin-11-yl）benzo[d]oxazole（BODPP）,2-（dipyrido[3,2-a:2’,3’-c]phenazin-11-yl）benzo[d]thiazole（BTDPP） andcharacterized by IR and elemental analysis.The Ru（II） complexes have also been achieved and characterized with IR,1H-NMR andelement analysis. The DNA-binding properties were investigated by means ofspectraphotometrics and viscosity measurements. The result reveals that the donor of attachedaryl substituent can play an important role on the DNA-binding properties of the complexes.Benzo[d]oxazole substituented ligand shows the stronger DNA-binding interaction. Benzenesubstituented ligand presents the poorer.