Reversible mechanofluorochromic luminescence behaviors of triphenylamine-based compounds and their application in erasable writing

It is challenging and desirable to develop an effective molecular design strategy to tune mechanofluorochromic (MFC) activity in organic molecules. Herein, three triphenylamine (TPA) derivatives were synthesized to investigate the MFC properties. The inclusion of iminodibenzyl, diphenylamine and carbazolyl units into the molecules causes some changes in the molecular conformation and packing pattern, which can lead to the variation of MFC activities. Among three TPA derivatives, T1 exhibits excellent MFC performance upon grinding. In addition, the color change induced by grinding is revisable upon heating. In consideration of the good repeatability and sensitivity of MFC process, T1 is chosen to prepare the rewritable papers and can be achieved in inkless writing technology.