Piezochromic Luminescence of Amide-substituted Pyrene Derivatives

Abstract

Pyrene derivatives having hydrogen bonding sites and π-πstacking sites change emission color from blue to greenish-blue by pressing, and restore to blue emission by heating.
To study effect of alkyl side chains on the piezocromic luminescent property, pyrene derivatives having various alkyl side chains were synthesized.
While the derivative having propyl side chain did not change emission color by pressing, those having hexyl, tetradecyl and ethylhexyl group changed and restored luminescent color by pressing and heating, respectively. The value of shift in luminescence wavelength was varied according to the alkyl chain. It was suggested that the structure of hydrogen bond-directed molecular assembly was affected by the size of the alkyl chain.