Conformationally-flexible and moderately electron-donating units-installed D-A-D triad enabling multicolor-changing mechanochromic luminescence, TADF and room-temperature phosphorescence.

A novel twisted donor-acceptor-donor (D-A-D) π-conjugated compound that contains flexible and moderately-electron-donating units has been designed and synthesized. It exhibited not only multi-color-changing mechanochromic luminescence and thermally activated delayed fluorescence, but also, unexpectedly, room-temperature phosphorescence in a host layer.