The Aggregation-induced Emission Properties Of Aryl-Substituted Pyrrole Derivatives With Chiral Attachment

Six triphenyl pyrrole derivatives: R-TPPBAm、S-TPPBAm、TPPBAm、TPP-bol、TPPpol、TPP-mol were designed and synthesized based on the nucleophilic substitution reaction between 1-(4’-phenyl carboxylical)-2,5-diphenyl pyrrole and phenylethylamine and menthol, sec-butyl alcohol, phenylethyl alcohol. Their structures were further characterized by 1H NMR, IR, MS and Elemental Analysis. Their Aggregation-induced/enhanced emission(AIE/AEE)were discussed, and the optical activity were explored through the detection of CD and CPL.All the target compounds R-TPPBAm, S-TPPBAm, TPPBAm, TPPbol, TPPpol, TPPmol exhibited obvious AEE properties, which mainly due to the addition of non-solvent water induced the molecular aggregation in the THF/H2 O mixtures, the aggregation inhibited the intramolecular motion and induced the non-radiation energy consumption, so that the fluorescence has been enhanced. The substituent and space configuration can influence the AEE properties of the target compounds.Both the enantiomers R-TPPBAm、S-TPPBAm exhibited obvious aggregation inducedcircular dichroism(AICD) feature with mirror-image signals. Besides, they also exhibits circularly polarized luminescence(CPL) and dissymmetry factor(gem) in aggregate state, and their gem were from 1.5×10-4 to 3×10-3 and-1.3×10-4 to-4×10-3, respectively. They could selfassemble into helical nanofibers with mainly left handed screw or right handed screw during the aggregating process in the mixted solution. The target compound TPP-pol formed nanofiber aggregation with helical configuration.TPPBAm in THF/H2 O mixture(fw=40%)exhibited no fluorescence, but with the addition of explosives, especially CL-20, the fluorescent turned on, and TPPBAm could be used to the detection of the explosives.