学科分类
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1 个结果
  • 简介:Tetraphenylporphyrin(TPP)isatypicalred-emittingluminogenshowingevidentaggregationcausedquenching(ACQ)effect.Toenhanceitsemissionefficiencyinsolidstate,fourtetraphenylethene(TPE)unitswereattachedtothefourmeso-positionsofTPPcoreviaestergroupthroughafacileandefficientroute.Thederivedcompound(4(TPE-COO)-TPP)emitsredfluorescence(peakat655nm)withagoodquantumefficiency(F)of7.5%,whichismuchhigherthanthatofTPP(Φ~0.1%).Inmolecularaggregateformedintetrahydrofuran(THF)andwatermixtures,4(TPE-COO)-TPPhasarelativehighFof12%.TheevidentlysubduedACQbehaviorcanbeascribedtothepropellershapeandbulkysizeoftheTPEunits,whichpreventtheclosepackingandstrongp-pinteractionofTPPcores.TheloosemolecularpackingandweakinterchromophoreinteractionswerevalidatedbydifferentcharacterizationmethodsincludingUV-visibleabsorption,steadystateandtransientfluorescencespectroscope,X-raydiffractionandscanningelectronicmicroscopeobservations.Itisnotedthat4(TPE-COO)-TPPhasanemissionefficiencyof14.4%indiluteTHFsolution.ThisisduetotheconjugationbreakbetweentheTPPandTPEmoieties,therotationalandvibrationalmotionsofthephenylgroupscannotquenchthefluorescenceof4(TPE-COO)-TPP.

  • 标签: Aggregation-induced EMISSION Tetraphenylethene PORPHYRIN Red EMISSION