Reversible Switching Emissions of Tetraphenylethene Derivatives among Multiple Colors with Solvent Vapor, Mechanical, and Thermal Stimuli

Luminogens exhibiting reversible multicolored emission
switching
in the solid state have been seldom reported, though they are of theoretical
and practical importance. Through introduction of weak interaction
to the propeller-like molecules, we obtained two tetraphenylethene
derivatives exhibiting morphology dependent multicolored emissions.
The emissions of the two compounds could be switched reversibly among
three colors in the solid state by reversible transformation among
three different aggregation states of the luminogens when treated
with different stimuli. Hence a possible strategy to construct luminogen
exhibiting reversible multicolored emission swithching is disclosed.