Study On Synthesis And Properties Of Azobenzene Bridged Cyclic BODIPY Oligomers And It’s Porphyrin Hybrids

Dipyrrole oligomers have received wide attention due to their ability to provide binding sites for metal ions and organic molecules.Among them,the boron complex of dipyrrole(BODIPY)is one of the most studied dipyrrole complexes.Because BODIPY has strong absorption and fluorescence quantum effect in the visible light region,high chemical stability,and relatively long excited state lifetime,it has been widely studied in the fields of fluorescence sensors,dye-sensitized solar cells,etc.On the other side,porphyrin is the most widely studied nitrogen-containing aromatic macrocyclic compound.Due to its good absorption and emission properties in the ultraviolet region,it has attracted much attention in the field of chemical sensors,solar cells,and light-harvesting materials.However,due to the weak absorption of the porphyrin monomer in the wavelength between from of 450 nm to 550 nm,its further application is limited.BODIPY has good absorption in this wavelength range,which Just makes up for the lack of absorption of porphyrin in this wavelength range.At the same time,azobenzene and its derivatives are considered to be useful in the field of photoresponsive conJugated molecules.The introduction of azobenzene is expected to make the properties and functions of porphyrin and BODIPY more diversified.In this paper,a series of azobenzene bridged cyclic BODIPY and its porphyrin hybrids were constructed by Suzuki coupling reaction,boronization reaction,condensation reaction,dehydrogenation reaction,fluoroboron complexation and metallation reaction.The main work of this thesis consists the following points:(1)On the basis of the literature,m-brominated azobenzene was synthesized from m-bromoaniline,and α-borides of pyrrole and dipyrrole were by Ir-catalyzed boronation reaction.A series of intermediates 5,6b and 7b were synthesized by Pd-catalyzed Suzuki coupling reaction using m-brominated azobenzene and α-borides of pyrrole and dipyrrole as the substrate.The intermediate was first subJected to a TFA-catalyzed condensation reaction,and then oxidized by oxidants such as chloranil or DDQ to synthesize azobenzene bridged dipyrrole oligomers 8 and 9 and 13 with an aldehyde group.An azobenzene bridged dipyrrole oligomer 14 was synthesized by TFA-catalyzed condensation reaction and Fluoroboration reaction of 13.These compounds were characterized by 1H NMR,characterization of Some Compounds by MALDI-TOF MS spectrometry,the structure of some compounds were confirmed by X-ray diffraction analysis.Their photophysical properties of these compounds were studied by UV/Vis absorption spectra,fluorescence emission spectra.(2)On the basis of the literature,various porphyrin monomers and their borides were synthesized.Intermediates 5 and 7 were condensed with p-bromobenzaldehyde under the catalysis of TFA to synthesize intermediates 21 and 25 with p-bromophenyl.Boride 22 was synthesized via bromine boronization of 21 under the catalysis of Pd.A series of azobenzene-bridged BODIPY oligomers of porphyrins were synthesized by Pd-catalyzed Suzuki coupling reaction and fluoroboration reaction of bromo,borides and intermediates of various porphyrin monomers.These compounds were characterized by 1H NMR,characterization of Some Compounds by MALDI-TOF MS spectrometry,the structure of some compounds were confirmed by X-ray diffraction analysis.Their photophysical properties of these compounds were studied by UV/Vis absorption spectra.It has been found that porphyrin hybrids have a wider absorption range than porphyrin monomers and have potential applications in light-harvesting materials.