Synthesis,Characterization Of Cu(?) Complexes Containing Ligands With Different Chromophore Groups

The transition metal copper complex with good luminescence properties,has been used as a substitute for precious metal elements complex and has been made great progress in dye sensitized solar cells(DSSC).In this thesis,in order to improve the light absorption capacity of the copper complex in the visible light region and prolong the life of the excited state,a series of Cu(I)complexes with different chromophore groups were designed and synthesized.All complexes were characterized by NMR,UV-Vis absorption spectroscopy,Fluorescence emission spectroscopy,etc.The effect of pyridylazole ligands with different substituents on the luminescence behavior of the complexes was investigated and tested by quantum yield and excited state lifetime.Meanwhile,DFT and TD-DFT methods were employed to classify the molecular frontier orbital contribution and the charge transition type.1.The ligands containing different electronic properties of 5-bromo-2-(1H-imidazol-2-yl)pyridine(L1),2-(1H-imidazol-2-yl)-5-methylpyridine(L2)and 2-(1H-imidazol-2-yl)-5-phenylpyridine(L3)were synthesized.Then,the POP ligand and copper tetraacetonitrile hexafluorophosphate [Cu(CH3CN)4PF6] is coordinated to form the corresponding complexes C1,C2 and C3.It is found that the lowest absorption peak of ultraviolet absorption spectrum is red-shifted because of C1 with electron-withdrawing properties and C3 containing conjugated ?.while the C2 of the electron-donating group is blue-shifted.The excited state lifetime and quantum yield did not change significantly.2.Organic chromophores containing different aromatic rings were introduced to parent molecule of pyridyl imidazole,and the ligands of 2-(1H-imidazol-2-yl)-5-(naphthalen-1-yl)pyridine(L4),2-(1H-imidazol-2-yl)-5-(phe nanthr-9-yl)pyridine(L5)and5-(indol-9-yl)-2-(1H-imidazol-2-yl Pyridine)(L6)were synthesized.Then,the complexes C4,C5 and C6 were synthesized by similar methods to characterize the effects of different organic chromophores on the optical properties.It was found that the lowest absorption peak of the UV absorption spectrum of complexes with the introduction of naphthalene,phenanthrene and anthraquinone chromophores was significantly red-shifted,and the molar absorption coefficient(?·L/mol·cm)was increased to more than 10,000.It is also extended by 40-50 ?s,but the quantum yield is lowered.3.The different chromophore groups were introduced into the parent molecules of pyridine imidazole through alkyne triple Bond.The ligands of 2-(1H-imidazol-2-yl)-5-(p-tolylthynyl)Pyridine(L7),2-(4-((4-methylnaphthalen-1-yl)e thynyl)phenyl)-1H-imidazole(L8)and4-((6-(1H-imidazol-2-yl)Pyridin-3-yl)ethynyl)-N,N-diphenylaniline(L9)and their corresponding complexes C7,C8 and C9 were synthesized.The effects of different connection methods on the luminescence behavior of the complex were explored through testing.It is found that the lowest absorption peak of the ultraviolet-visible absorption spectrum of the three complexes is obviously red-shifted,the molar absorption coefficient(?·L/mol·cm)is increased to more than 22,000,and the excited state lifetime is also extended by 60-70 ?s,but quantum yield has decreased.4.The electronic structure and charge transition types of all the above complexes were attributed by quantum theory calculation and density function theory(DFT).