Tetrahydro[5]helicene-based dye with remarkable and reversible acid/base stimulated fluorescence switching properties in solution and solid state

•A new imide dye based on tetrahydro[5]helicene skeleton was synthesized.•The dye exhibited TFA/TEA stimulated fluorescence switching properties in both solution and solid state.•The switchable behavior was evidenced by the 1H NMR experiments and theoretical calculations.

A new organic imide dye based on tetrahydro[5]helicene skeleton was synthesized, and its helical structural feature was confirmed by the crystal structure. It was found that the dye exhibited remarkable and reversible acid/base stimulated fluorescence switching properties in both solution and solid state, in which the dye was changed from “D–A type” to “A–A type” in the presence of TFA, and returned to its original form upon the addition of TEA. This switchable behavior was also evidenced by the 1H NMR experiments and theoretical calculations.

Graphical abstractA tetrahydro[5]helicene-based imide dye was synthesized, which exhibited remarkable and reversible acid/base stimulated fluorescence switching properties in both solution and solid state.Figure optionsDownload full-size imageDownload as PowerPoint slide