Design,Synthesis,and Performance Study Of Thiadiazole Quinoxaline Compounds

The greater the number of fused rings and the stronger the conjugation in the molecular structure are more conducive to the application of molecules in organic optoelectronic devices.However,with the increase in the number of fused rings,the stability of compounds decreases and their solubility deteriorates,which greatly limits their practical application as active organic semiconductor materials.To solve this problem,some researchers have begun to achieve the transformation of organic semiconductor materials and performance improvement by adjusting the number and arrangement of condensed rings in polybenzenes,as well as embedding different types,numbers,and positions of heteroatoms or electron withdrawing groups.Among them,the introduction of nitrogen atoms to construct azabenzene compounds and make them become N-type organic materials is a hot issue in research.Currently,the diversity of N-type organic molecules is limited,and high-performance N-type organic semiconductor materials with high electroluminescence are very scarce,resulting in significant limitations in their application in organic electronic devices.Azapolybenzene compounds have been proven to be excellent N-type organic semiconductor materials due to their strong electronic affinity,high stability,and good solubility.Therefore,it is extremely important to design and synthesize high mobility azapolybenzo compounds and expand their applications.This thesis summarizes the development,structural characteristics,synthesis methods,and applications of common P-type organic conjugated small molecular materials to N-type organic conjugated small molecular materials in field effect transistors.Through summary,it is found that azabenzene compounds in N-type organic conjugated small molecules can exhibit high performance in organic field effect transistors due to their easy structure regulation,and are a new type of organic semiconductor material.Therefore,we have conducted research around the design and synthesis of azapolybenzene systems,and designed novel asymmetric azapolybenzene molecules to regulate the nonmolecular energy levels,molecular stacking orientations,etc.of the materials,in order to achieve high mobility and high electroluminescence N-type semiconductive materials.The structure of the compound was determined by ¹H NMR,¹³C NMR,MS,and single crystal analysis.The optical and electrochemical properties of the compound were studied.（1）Synthesis and properties of thiadiazole quinoxaline compound M₁-M₃A series of fluorophenanthrenedione,benzophenanthrenedione g,and benzoyl h with different conjugation properties were designed and synthesized,which were fused to the4,7-dibromo-5,6-dinitrobenzothiadiazole of TIPS substituted dibromo,respectively,to further expand the conjugation structure.The thiadiazole quinoxaline compounds M₁-M₃were successfully prepared.The influence of the rigid structure of the compound on its performance was analyzed.By analyzing the single crystal structure of the compounds,it was found that all three compounds have strongπ-πstacking,and their photoelectric properties and thermal stability were studied.（2）Synthesis and Properties of Thiadiazole Quinoxaline Compounds M₄-M₆Fused with Perylene ImideA novel perylene diimide fused thiadiazole quinoxaline azapolybenzobenzene compound M₄-M₆ was designed and synthesized.The synthesis process of these compounds was introduced in detail.Using acenaphthene as the starting material,perylene di imide with diketone functional group was obtained through bromination,substitution,coupling,cyclization and oxidation,and then condensation reaction was carried out with diamine compound 7 to construct thiadiazole quinoxaline azabenzene compounds fused with perylene di imide with different substituents.By studying the thermal,optical,and electrochemical properties of M₄-M₆,it was found that they all have high thermal stability,wide absorption range,and high electron affinity.