Design,Synthesis And Properties Of Novel Porphyrin Luminescent Liquid Crystals

Porphyrin is an important member of aromatic macrocycles with unique optoelectronic properties and excellent stability.It plays an important role in agriculture,industry,medical science,defense and other fields.As organic luminescent molecules,porphyrins also have a wide range of uses in the field of optical materials.However,fluorescence quenching easily in the aggregated state limits their application and development.Therefore,development of porphyrin molecules with aggregation-induced emission effect will produced the broader application prospects in light-emitting devices.At present,the introduction of long alkyl chains,chiral units or aggregation-induced emission groups into molecules to endow liquid crystal,aggregation-induced emission and circularly polarized luminesence functions is an important research field of optical materials through appropriate molecular design methods.This paper focuses on the transformation of porphyrin molecules into functional porphyrin molecules with both liquid crystal properties,aggregation-induced emission and circularly polarized luminescence as well as systematic study on their derivation and various optical physical properties.Details were as follows:1.Three kinds of porphyrin liquid crystals with flexible chains of different lengths have been designed and synthesized,which have good fluorescence properties and excellent hexagonal columnar liquid crystal texture.It was also found that the length of the alkyl chain has a certain influence on its liquid crystal range.The longer the length of the alkyl chain,the wider the liquid crystal temperature range.2.Porphyrin derivatives with chiral binaphthol were designed and synthesized.Novel porphyrin molecules have the highest fluorescence emission intensity when they reach a certain water fraction,and they have solid fluorescence emission.CD and CPL tests have proved that they have good circularly polarized luminescence performance.3.Two different chiral camphor porphyrin molecules were designed and synthesized.Fluorescence spectra confirmed that new porphyrins have good solid luminescence properties.CD and CPL spectra demonstrated their good circularly polarized luminescence properties.4.A porphyrin derivative with cholesterol unit was designed and synthesized.The molecule also has certain solid fluorescence emission.POM and XRD results confirmed its hexagonal columnar liquid crystal morphology.CPL test found that the chiral inversion phenomenon existed in the liquid crystal films compared with ordinary solid films.5.A chiral porphyrin molecule with aggregation-induced emission properties were designed and synthesized.It is proved that there is a good fluorescence resonance energy transfer effect between cyanostilbene molecules and porphyrin units.It exhibits focal cone texture.The XRD patterns show that it is hexagonal columnar phase liquid crystal morphology.CPL test has proved that it has good circularly polarized luminescence performance.The chiral inversion phenomenon was found in the liquid crystal film.