Aggregation-induced emission enhancement (AIEE)-active tetraphenylethene (TPE)-based chemosensor for CN-

An aggregation-induced emission enhancement (AIEE)-active fluorescent sensor has been successfully designed and synthesized, combining the AIE effect of tetraphenylethylene (TPE) with the cyanide acceptor of phenanthro [9,10-d]imidazole. The sensor exhibits not only the property of AIEE in DCM/n-hexane or THF/H2O, but also the phenomenon of mechanofluorochromic (MFC). It displays large Stokes shift (107 nm) due to the intramolecular charge transfer (ICT) process. The cation of CN- boosts the ICT process to make the greater Stokes shift (184 nm) with the fluorescent color vary from blue-green to sodium-yellow and visually turning from light yellow to dark yellow in the naked eyes. The results of Job's plot, ESI-MS and the DFT calculations provide the stoichiometric ratio and electronic properties of the sensor. Furthermore, the sensor could be applied to qualitative and quantitative detection of CN- on test paper strips. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The designed AIEE-active fluorescent sensor combines the AIE effect of tetraphenylethylene with the cyanide acceptor of phenanthro[9,10-d]imidazole, exhibiting AIEE and MFC properties in DCM/n-hexane or THF/H2O, along with a large Stokes shift and ICT process.