Multicolor fluorescence switching material induced by force and acid

A novel D-A-D chromophore TBQM based on triphenylamine, acylhydrazone and dimethylamino was synthesized, and the emission properties of TBQM was studied in solutions as well as in aggregated state. TBQM showed obvious solvatochromism in different solutions. In addition, the reversible multicolor fluorescence switching properties under the stimulation of external forces and acid were also obtained. The fluorescence of TBQM changed from blue to bright blue, and finally to blue-green as the degree of grinding increased, which would recover after being fumigated by CH₂Cl₂. Meanwhile, TBQM could undergo twice protonation after fumigated by TFA. The fluorescence color changed from blue to bright blue, blue-green, and yellow-green until the fluorescence was quenched with the increasing of TFA fumigation time, which can be restored automatically or by TEA fumigation. Moreover, TBQM could be used as an advanced fluorescent anti-counterfeiting ink.