Six anthracene-based A−D−A fluorescent compounds were synthesized through precise modulation of number and arrangement of nitrogen atoms. Comprehensive investigation of the photophysical properties of these six molecular structures was conducted both in solution and solid phases. Notably, all six compounds exhibited distinct mechanofluorochromic characteristics within the solid-state.

Abstract

The mechanofluorochromic (MFC) characteristics of anthracene-based acceptor-donor-acceptor (A−D−A) fluorescent molecules are explored through a comprehensive investigation of their photophysical behaviors. Six 9,10-diheteroarylanthracene derivatives with varying acceptor groups (pyridin-4-yl, pyridin-3-yl, pyridin-2-yl, pyrimidin-5-yl, pyrazinyl and quinoxalinyl) are synthesized and systematically characterized. The photophysical properties in both solution and solid-state are examined, revealing subtle yet significant influences of the spatial arrangement and number of nitrogen atoms within the acceptor group on fluorescence emission. Single-crystal structures of these compounds provide insights into their steric configurations and intermolecular packing modes, offering valuable insights into the fundamental mechanisms that underlie the observed MFC properties. This study illuminates the intricate interplay between MFC properties and the refined molecular structure, thus presenting promising avenues for the design and advancement of novel MFC materials.