Synthesis And Photophysical Property Study Of Small Molecules Red Materials Based On Tetrathienylethene Or Benzothiadiazole Core

In 2001,Tang and co-workers first discovered the momentous aggregation-induced emission(AIE)phenomenon,and fluorescent materials have been greatly developed.Herein,we have designed and synthesized a series of small AIE molecules,and studied them from the aspects of high fluorescence quantum efficiency,piezofluorochromic and biological imaging.We designed and synthesized a series of branched red AIE molecules TTE-4TPA,TTE-4DPT and TTE-4DTPA based on tetrathienylethene(TTE)core and various branched triphenylamine(TPA)analogue(triphenylamine(TPA),N,N-diphenylthiophen-2-amine(DPT)and N,N-diphenyl-4-vinylaniline(DTPA))end group,respectively.It has been found that these molecules have aggregation induced emission(AIE)effect,and the highest fluorescence quantum efficiency is TTE-4TPA up to 10.6 %.TTE-4TPA and TTE-4DPT have piezofluorochromic effect with a over 100 nm red shift for TTE-4TPA.TTE-4DTPA can specifically stain cell membrane with Rr = 0.95,with excellent photo-stability.A family of red molecules(TBTA,TBTA-C and TBDA)with high fluorescent quantum efficiency were synthesized based on benzothiadiazole(BT)with tetraphenylethene(TPE)to improve the fluorescence quantum efficiency and to build the D-?-A conjugated systems.The fluorescent emission wavelengths of these molecules are all around 600 nm,and the fluorescence quantum efficiency of both solids and solutions are above 50 %.