Touch-sensitive yellow organic mechanophosphorescence and a versatile strategy for white organic mechanoluminescence

Abstract

Organic mechnoluminescence can be divided into mechanofluorescence (MF) and mechanophosphorescence (MP), and MF materials have been reported more but MP ones are rather rare at present. Herein, we report an organic MP crystal that can produce bright mechanical-induced phosphorescence afterglow like a comet across the sky in the dark upon grinding. The photoluminescence and single crystal analyses indicate that the bright MP afterglow benefits from its highly-efficient and long-lived room temperature photo-phosphorescence and piezoelectric space group nature. Meanwhile, a new organic MF crystal is also developed. With bright blue MF and yellow MP crystals in hand, we demonstrate that, for the first time, tunable and unattainable organic MF–MP dual emission and even white ML, not the common photo-induced dual emission and white light, can be obtained by strategic physical mixing.