Design And Synthesis Of Dihydrohexaazapentacene And Pyrene Based Organic Semiconductors

Organic semiconductors,compared with inorganic semiconductors are advantageous in chemical versatility and easy fabrication.Organic semiconductors exhibit bright application prospect inflexible and soft organic optoelectronic devices and have obtained widespread researches interest.Great improvement has been made in the synthesis of high performance organic semiconducting frameworks and device fabrication technology.However,some challenges still remain.Such as,stable and high performance semiconductors are rare and the understanding of the structure-property relationship is not well.Therefore,designing new stable conjugated organic semiconductors is of vital importance to the exploration of structure-property relationship.In this thesis,we focus on the design and synthesis of new and stable conjugated organic semiconductors.We successfully synthesized a new stable hexaazapentacene framework and got a further investigation into its physicochemical properties.Besides,We explored the synthesis strategy of a two dimensional semiconductor based on perylene tetracarboxylic diimide(PDI).The specific work is illustrated as:1.A new dihydrohexaazapentacene(DHHAP)containing pyridine and pyrazine hybrid structure has been successfully designed and synthesized.The tautomerism,halochromism and aromaticity of DHHAP were investigated.DHHAP is obtained through a concise condensation reaction without solvent.1H NMR spectroscopy,ultra-violet and visible spectroscopy investigation witnessed its existence of two benzenoid and quinonoid tautomers in polar solution.In acid condition,benzenoid structure will transfer into quinonoid structure,and there exists two diprotonated [DHHAP-q] H22+ species.DHHAP also exhibits remarkable stability.The stability and aromaticity of DHHAP is explored by Density functional theory(DFT)computation,including heats of hydrogenation(?H(H2)),nucleus independent chemical shift(NICS)and anisotropy of the induced current density(ACID).The computation results indicate that the 4n ?DHHAP is “global aromatic”.Furthermore,to enhance the solubility of DHHAP,6,13-bis((triisopropylsilyethynyl))-1,5,7.8,12,14-hexaazapentacene(TIPS-HAP)is designed andthe synthetic routes are explored.2.Two dimensional conjugated pyrene and perylene tetracarboxylic diimide(PDI)was designed.2,9-di-tert-butyldibenzo[fg,op]tetracene is successfully synthesized by straightforward Suzuki coupling and cyclization reactions.The reaction condition of Suzuki coupling is optimized.2,9-di-tert-butyldibenzo[fg,op]tetracene and 6,11-diphenyl-N,N-bis(henicosane)perylene tetracarboxylic diimide.Pyrene derivative even has strong fluorescence in the solid state,which may be used in organic light emitting transistor(OLET).