Fluorescence Properties of Cyclic Enolate-Modified 4-(4-(N,NDiphenylamino)styryl)pyridinium Betaine Dyes

摘要

Red emitting organic dyes have received much attention due to their potentials forapplications in the fields of optoelectronics,bioanalytical science,medical science,and so on.However,not so many examples of highly efficient red emitters have so far been reported.In2017,Ritchie and coworkers reported that pyridinium-cyclic enolate betaine derivativesexhibit highly efficient fluorescent emission.1 This is the first report of pyridinium-cyclicenolate betaine derivatives as highly efficient fluorophores and suggests that the betaineskeleton has a great potential to achieve highly efficient fluorescence.On the other hand,the4-(4-(N,N-diphenylamino)styryl)pyridinium (DSP) dye is known as a red fluorophore,although the emission is very weak.2 In this study,we develop highly efficient red fluorescentbetaine dyes by incorporating a 1-pentafluorophenyl-4-oxy-3-maleimidyl group into the DSPskeleton.We report their fluorescence properties by comparison with N-methyl DSP derivative(DSP-Me,Fig.1).