Regioselective Functionalization Of BODIPYs And?Synthesis Of Their Oligomers

Boron dipyrrole(BODIPY)has attracted much attention because of its remarkable optical properties,good light stability,and multiple modification sites in its parent backbone.Regioselective functionlization of BODIPY can effectively modulate its optical properties(ab sorpti on/emi ssion wavelength,fluorescence quantum yield/lifetime,triplet/singlet quantum yield,etc.)and in order to promote the further application of BODIPY in related fields(fluorescent dyes,photosensitizers,fluorescent probes,organic photoelectric materials,etc.),it is designed to synthesize new functional molecules with promising applications in materials and biology.This paper has carried out a series of studies centering on this issue.This thesis mainly consists of three chapters:First,a novel method for the selective synthesis of 3,5-arylated BODIPY from BODIPY and aryl diazonium salts was developed under visible light induction.The reaction does not require adding any catalyst,and BODIPY self-catalyzed photochemical reactions are first realized by using BODIPY's own singlet excited state 1PS as a reducing agent to react with an aryl diazonium salt to produce BODIPY cation radicals and aryl radicals.This method only requires the use of common white light,by changing the equivalent weight of the aryl diazonium salt and controlling the reaction time,it is possible to synthesize a highly selective monosubstituted,biarylated BODIPY with a good substrate universality.By changing the substituent group on the aryl diazonium salt,the optical properties of the product can be controlled,which provides a new idea for the application of BODIPY as a photosensitizer in photocatalytic reaction and the regi osel ective functi onalizati on.Second,by screening different oxidation conditions,a method of synthesizing BODIPY oligomers with different coupling methods and different degrees of polymerization with a high-yield "one pot method" using molybdenum pentachloride as an oxidant was developed.Among them,the product 4 with the alpha-position tetramerization is dominant,with a maximum yield of 34%and has a good regioselectivity.At the same time,the ability of molybdenum pentachloride and ferric chloride to oxidize 3-aryl BODIPY was compared.These oligomers have good spectral properties,with the increase of the degree of polymerization,the wavelengths of UV absorption and fluorescence emission have undergone a large red shift,and the wavelength of the modified BODIPY 4P2 has reached 938 nm,which has good fluorescence emission in NIR-?and has potential applications in vivo fluorescence imaging.Third,two methods for the selective introduction of nitro groups in the 3-position of BODIPY were developed.Among them,the yield of nitroxyl tetrafluoroborate nitrate was up to 85%,and then reduced to amino-substituted BODIPY.At the same time,a method for synthesizing amino substituted products from the 3-chloro-BODIPY was developed.The N-bridged BODIPY oligomers were obtained with high yields and high regioselectivity using a simple nucleophilic substitution method.It can be seen from the spectral test results that the 7r-electrons between the BODIPY precursors can be effectively conjugated via the N-bridge,resulting in a large degree of red-shift of the absorption wavelength,and these new N-bridged BODIPY molecules have potential applications in conducting materials.