局域和长程杂化密度泛函研究推拉结构有机发光分子.pdf

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1、物理化学学~E(WuliHuaxueXuebao)1640ActaPhys．一Chim．S2011，27，1640-1646July[-Article]v，、Ⅳw．whxb．pku．edu．cn局域和长程杂化密度泛函研究推拉结构有机发光分子刘小君王宁程浩(北京交通大学发光与光信息技术教育部重点实验室，北京100044)摘要：用含时密度泛函方法研究了具有推拉结构的有机发光材料3-(二氰亚甲基)-5，5-·二甲基-1·(4‘【9‘咔唑基卜苯乙烯基)环己烯(DCDCC)的吸收和荧光光谱，并考虑了溶剂效应．通过与实

2、验光谱的比较，重点评价了包括局域和长程存内的8种交换泛函．结果表明泛函的选择对结果的可靠性至关重要，在密度泛函和含时密度泛函理论框架下，包含44％HartreeFock交换泛函的BMK杂化函数联同连续极化模型和中等大小的基组最适合研究DCDCC分子的光谱性质．此外，尽管DCDCC分子内电荷转移并没有强致发出双荧光，但仍然可以用平面分子内电荷转移和扭转分子内电荷转移模型解释DCDCC激发态的结构．BMK泛函计算的结果表明DCDCC的激发态结构支持平面分子内电荷转移模型．关键词：长程杂化泛函：局域杂化泛函：含时

3、密度泛函理论：分子内电荷转移中图分类号：0641LocalandLong—RangeHybridDensityFunctionalStudyonanOrganicLight,-EmittingMoleculewithPull-PushStructureLIUXiao-JunWANGNingCHENGHao(KeyLaboratoryofLuminescenceandOpticalI}mationMinistry0fEducnt{on．BeijingJiaotongUnNersity,Beijing10004

4、4．户．China1A=bstract：Theabsorptionandfluorescencespectraof3-(dicyan0methyIene)-5，5-dimethyl-·1一(4一【9一carbazo1]-．styry1)cyclohexene(DCDCC)，anorganiclightemittingmaterialwithpulpushstructure，wereinvestigatedusingatime．dependentdensityfunctionaltheory(TD-DFT)a

5、pproachandbulksolventeffectsweretakenintoaccount．Theperformanceofeightexchange．-correlationfunctionalsincludingbothlocalandlong—rangehybridswasassessedbycomparingthecalculatedelectrontransitionenergiestoexperimentalobservations．1tturnsOUtthaftheappropriate

6、choiceoffunctionalsiScruciaItOobtainanaccuratevalueandBMKhybrids．whichcontain44％HartreeFockexchange，intheframeofDFTandTD—DFTwiththepolarizablecontinuummodelandamediumsizedbasisset，emergesasanefe,ctivestrategyforDCDCC．Moreover．，theplanarandtwistedintramolec

7、ularchargetranslfer(PICTandTICT)modelswereusedtointerprettheexcitedstatestructureofDCDCCafhoughthechargetransfercharacteroftheexcited—statewasnotasintenseastoemitobviousdoublefIuOrescence．TheaccuratestructureswereoptimizedbvBMKandsupportedthePICTmode1．KeyW

8、ords：Long·．rangehybrid；Localhybrid；Time．一dependentdensityfunctionaltheoryIntramolecularchargetransferReceived：March21，201I；R'evised：May13，2011；PublishedonWeb：May25．2011Correspondingauthor．Email：xjliu@bjmedu．c