Synthesis And Properties Of Novel Cyclic And Linear Conjugated Organic Materials

Since the Japanese researcher Shirakawa Hideki won the Nobel Prize for discovering the conductive polymer polyacetylene in 2000,conjugated organic materials and conjugated polymers have attracted extensive attention of many scientific researchers and developed rapidly.Conjugated organic material,as an emerging optoelectronic material,has many advantages such as diverse and adjustable performance,light weight,and good processing performance.They have been widely used in important fields such as field-effect transistors,light-emitting diodes,and solar cells.In recent years,in order to meet more and higher performance requirements in practical applications,the construction of new conjugated organic materials has quickly become a research hotspot in this field.Based on their understanding of the close relationship between the molecular structures and performances,many researchers have designed and developed a series of conjugated organic materials with novel structures and excellent performances.This thesis studied the synthesis and properties of two new conjugated organic materials.The main contents are as follows:1.Synthesis and properties of cyclic molecules based on[2.2]paracyclophaneBy Suzuki-Miyaura coupling and reduction aromatization,we synthesized a[2.2]paracyclophane-containing macrocycle(PCMC)as a new through-space conjugated macrocycle using only benzene groups as the skeleton.For comparison,diphenylmethane-containing macrocycle(DCMC)with a non-conjugated linker was also synthesized.Their structures were confirmed by NMR and HR-MS,and their photophysical properties were studied by UV-vis and fluorescence spectroscopies combined with theoretical calculations.Next,we investigated the chirality of PCMC through temperature-variant nuclear magnetic resonance(VT-NMR)experiments,and verified that it is a dynamic racemization process with the rubber glove mechanism.Meantime,we studied the temperature effects of the photophysical properties of PCMC through temperature-variant UV-vis and fluorescence spectra.2.Synthesis and properties of linear polymers based on hexabenzocoronene(HBC)A PPE-type linear conjugated polymer(PHE)based on HBC molecules was synthesized by a Sonogashira coupling reaction catalyzed by palladium catalyst.The molecular structure of PHE was confirmed by 1H-NMR,GPC,FTIR,and Raman techniques.The photophysical properties of the target material were investigated by UV-vis and fluorescence spectroscopy.The results show that that PHE has a redshift of>100 nm in both spectra compared to PPE.In addition,the concentration effect of its fluorescence spectrum was studied to reveal the molecular aggregation behavior,and the SEM results also showed its interesting self-assembly property.