Achieving high-contrast tricolor emissive regulation of a single-component molecule using a single type of external stimulus is highly desirable but challenging. In the present study, we report a symmetric acceptor-donor-acceptor (A-D-A)–type aggregation-induced emission-active luminogen, which displays a sequential high-contrast fluorescence switching just by anisotropic mechanical grinding. Specifically, upon light grinding, an orange–yellow-to-blue hypsochromic mechanofluorochromic response with a distinct color contrast (change in the maximum emission wavelength, Δλ _em,max = 122 nm) is noticed, and the slightly ground solid exhibits a blue-to-red high-contrast (Δλ _em,max = 185 nm) bathochromic mechanofluorochromic conversion upon vigorous grinding. Thus, using a single luminogen developed here, we can realize wide-range (Δλ _em,max > 100 nm) hypso- and bathochromic fluorescence mechanochromisms simultaneously. The tricolored mechanofluorochromic phenomenon is attributed to two different morphological transitions involving crystalline-to-crystalline and crystalline-to-amorphous states. Furthermore, three information anticounterfeiting systems are developed using the luminogen presented here.

Eight new anisotropic force-triggered high-contrast tricolor fluorescent molecular switches are developed via a high-efficiency molecular engineering strategy. Furthermore, three advanced high-security anticounterfeiting systems are constructed.

A gold( i ) complex with a phosphino-type ligand can simultaneously show AIE and high-contrast tricolored mechanofluorochromism for the first time, and its application in inkless writing information storage is developed.