Piezochromic luminescence of excimers formed by anthracene plane slip.

Excimer materials are frequently applied to organic chemistry, optoelectronic devices and stimulus response. Specific research on the entire process of excimer generation in solid materials, as well as the intricate mechanism of piezochromic luminescence based on excimer, are still absent and need to be examined in-depth through comprehensive experiments. Therefore, we designed an anthracene-based molecule CZPAN , which adopts no overlap area between anthracene molecules in its crystal at ambient conditions, to investigate the piezochromic luminescence behavior and expect the anthracene group to form excimers under high-pressure stimulation. As pressure increases, CZPAN gradually changes from blue monomer luminescence to green excimer luminescence accompanied with the considerably red-shifted emission spectra, and exhibits a discontinuity of fluorescence quenching during the formation of excimers (in the pressure range of 5.3–6.6 GPa). Moreover, the pressure relief process is fully reversible. This study presents abundant piezochromic luminescence of CZPAN and proves that the formation of excimers requires a certain overlap area between molecules. Pursuing the appropriate strength of π–π interactions will thus be the focus of future research on excimer materials of high luminescence efficiency, so that excimers can be better applied in sensors and imaging devices. [Display omitted] • There are no overlap areas between anthracene molecules in the designed crystal at ambient conditions. • High pressure induces the formation of excimers. • The designed crystal shows abundant phenomena of piezochromic luminescence during compression. • High luminescence efficiency of excimers requires the appropriate strength of π–π interactions. [ABSTRACT FROM AUTHOR]