Design,Sythesis and Properties of Organic Optoelectronic Materials Based on Triazatruxene

Author:Li Xiang Chun

Supervisor:huang wei lai wen yong


Degree Year:2018





Organic optoelectronic materials,because of their excellent photoelectric properties,have been widely used in organic light emitting diodes,organic photovoltaics,organic field effect transistors,organic biosensors,energy storage devices,etc.The energy level and photoelectric properties of the organic optoelectronic materials could be effectively adjusted by changing the p-type or n-type segments and connections to obtain high-performance and stable optoelectric materials and devices.In this study,a series of organic photoelectric materials based on p-type triazatruxene were designed and synthesized.The effects of the number of arms,the bonding type,the molecular configuration and the conjugated structure on the photoelectric properties were systematically studied.In the thesis,the new synthetic method for substitutional position-determined tribromotriazatruxene was developed;the new mechanism for achieving white OLED based on intramolecular excimer was proposed;the new applications of triazatruxene in gas detection and energy storage were expanded;the new structure of larger planar andπ-extended diindolotriazatruxene was designed and synthesized.The detail reseaches are as follows:By selecting the raw materials and optimizing the reaction conditions,two tribromotriazatruxene isomers 2,7,12-TriBrTAT and 3,8,13-TriBrTAT were designed and synthesized.The problem of uncertain substitutional positions by direct brominating triazatruxene was solved.The conjugated effect of two isomers was studied by theoretical calculations.It was found that 2,7,12-TriBrTAT is a long-range conjugation,while 3,8,13-TriBrTAT is a short-range conjugation.The conjugated difference of two isomers makes the difference in the properties of the photoelectric materials and devices,which provides a guide for the design and synthesis of photoelectric materials based on triazatruxenes.By adjusting the number of arms,TP1,TP2,and TP3 were designed and synthesized,which was applied in the solution-processed OLEDs.By combining theoretical calculation with experimental study,the influence of the number of arms on the photophysical and electrochemical properties of the materials was studied in detail.The design strategy of white OLED materials based on intramolecular excimer was proposed,which provides a new method for developing the new white OLED materials.The white OLEDs based on TP3 has exhibited stable white emission with a turn-on voltage of 3.8 V,a high brightness of 3361 cd m-2,a current efficiency up to 1.43 cd A-1 and CIE coordinates of(0.38,0.38).By introducing a new-C=N-bonding connection,the triazatruxene derivative(TATNFF)was designed,synthesized,and explored as a sensitive probe to detect HCl gas.The probe displayed good selectivity and sensitivity(Limit of Detection:161 ppm,Response Time:10 s)for HCl.In addition,the detailed binding modes of the probe TATNFF were confirmed by experimental and theoretical studies,further revealing the fluorescence mechanism,which opens up a new strategy to explore a novel set of smart responsive materials for sensing applications.By constructing a new material configuration,two conjugated microporous polymers based on triazatruxene(TAT-CMP-1 and TAT-CMP-2)were successfully designed and synthesized to explore their potential application as efficient and stable electrode materials for energy storage.At a current density of 1 A g-1,TAT-CMP-1 and TAT-CMP-2 showed a high specific capacitance of 141F g-1 and 183 F g-1,respectively.They exhibit unusually high capacitance per unit surface area(>160 mF cm-2)which is among the highest values obtained for supercapacitors.Moreover,they showed little capacitance decay(17%for TAT-CMP-1 and 5%for TATCMP-2)after 10 000charge-discharge cycles at a high current density of 10 A g-1.This study has demonstrated the very promising potential of nitrogen-rich triazatruxene-based conjugated microporous polymers for applications in high-performance energy storage devices.Based on synthesis mechanism of triazatruxen and the previous researches,a unique planar and highlyπ-extended scaffold diindolotriazatruxene(DIT),was synthesized for the first time through rational molecular design.A combination of the thermal,optical,electrochemical investigation and theoretical calculation confirmed the electron-rich characteristics and chemical modificationof the resulting DIT unit,demonstrating the promise as a building block to construct highly organic optoelectric materials.The butterfly-shaped compouds 4Py-DIT and 4PyF-DIT based on DIT core showed blue-green emission,high thermal stability and photoluminescence quantum efficiency,which indicates DIT is a great promising organic photoelectric material building unit.