Design And Synthesis Of Bodipy Sensitized Iridium Complex Photoelectric Functional Materials

Cyclometallated iridium???complexes have wide applications in the fields such as chemical bioprobes,electroluminescence,etc.due to their unique photophysical and chemical properties.However,due to its weak absorption of visible light and its short triplet excited lifetime,the research in the field of photoelectrochemistry is limited.The photophysical and electrochemical properties of the iridium complex depend on the properties of the ligand.When the ligand is modified with certain substituents,the presence of the substituents will cause a significant change in the photophysical and electrochemical properties of the iridium complex.Based on this,the organic fluorescent group is introduced into the ligand of the iridium complex,and its advantages of strong absorption of visible light and high fluorescence quantum yield are used to sensitize the absorption capacity of the iridium complex to visible light and obtain a long-lived triplet excited state for better application to the field of photoelectrochemistry.This thesis is divided into the following three parts:The first part introduces the structural properties of metal iridium complexes and summarizes its research progress in the fields of chemical biological probes,organic light emitting diodes?OLED?,dye-sensitized solar cells?DSSC?,organic photovoltaic cells?OPV?,etc.Finally,the research status of iridium complexes in the field of photoelectrochemistry is introduced.In the second part,by introducing fluorescent dye molecules with strong absorption in the visible region in the auxiliary ligand,4-?2-pyridyl?benzaldehyde?CHO-ppy?and phenylpyridine phosphate?ppy-PE?are used as main ligand,5-ethynyl Bodipy-2,2?-bipyridine?bpy-E-BDP?,7-diethylamino-coumarin-ophenanthroline?C-DIEA-phen?,ophenanthroline Bodipy?phen-BDP?,bipyridine Bodipy?bpy-BDP?are uesd as a ancillary ligand to synthesize the complex[Ir?CHO-ppy?₂?bpy-E-BDP?]PF₆?Ir-1?,[Ir?CHO-ppy?₂?C-DIEA-phen?]PF₆?Ir-2?,[Ir?ppy-PE?₂?phen-BDP?]PF₆?Ir-3?,[Ir?ppy-PE?₂?bpy-BDP?]PF₆?Ir-4?.The UV-Vis absorption spectrum and photoelectric properties are studied.The results show that the complexes Ir-1?Ir-4 prepared after introducing the fluorescent group all have strong light absorption at 540,450,503,505 nm respectively.The molar absorbances are 20000,45000,31000,28000 M^-1·cm^-11 respectively.Compared with the traditional iridium complexes,the absorption capacity in the visible light region has been significantly improved.Under the excitation of the corresponding wavelength light,the prepared complex can produce a stable cathode photocurrent.The photocurrent density is 72,104,252,160 nA/cm² respectively.In order to further improve the photocurrent efficiency,Ir-1 and Ir-2 are used to sensitize Ni O.The photocurrent density is 1.6 and 2.6?A/cm²,and the photocurrent intensity is increased by 22,25times,respectively,and can be used in the field of photoelectrochemistry.The study of the photoelectric properties proves that the complex has better photoelectric conversion ability and stable photocurrent,which is an ideal material suitable for the field of photoelectrochemistry.The third part,by introducing fluorescent dye molecules with strong absor ption in the visible region in the main ligand,2-?4-Bodipy phenyl?pyridine?4-ppy-BDP?,2-?3-Bodipy phenyl?Pyridine?3-ppy-BDP?are uesd as the main liga nd,2,2?-bipyridine-4,4?-diphosphate?bpy-PE?,2,2?-bipyridine-4,4?-dicarboxylic acid?bpy-COOH?as a ancillary ligand to synthesize the complex[Ir?4-ppy-B DP?₂?bpy-PE?]PF₆?Ir-5?,[Ir?3-ppy-BDP?₂?bpy-PE?]PF₆?Ir-6?,[Ir?4-ppy-BDP?₂?bpy-COOH?]PF6?Ir-7?,[Ir?3-ppy-BDP?2?bpy-COOH?]PF6?Ir-8?.The UV-Vis absorption spectrum and photoelectric properties are studied.The results show that the c omplexes Ir-5?Ir-8 prepared after the introduction of the fluorescent group all h ave strong light absorption at 509,507,512,515 nm respectively.The molarab sorbances are 39000,39000,40000,43000 M^-1·cm^-11 respectively.Compared wit h the traditional iridium complexes,the absorption capacity in the visible regio n has been significantly improved.Under the excitation of the corresponding w avelength of light,the prepared complex can produce a stable cathode photocur rent.The photocurrent density is 160,220,170,240 nA/cm² respectively.The s tudy of the photoelectric properties proves that the complex has better photoele ctric conversion ability and stable photocurrent,which is an ideal material suita ble for the field of photoelectrochemistry.