Modulation of the Mechanical and Emission Properties of Cyano-Substituted Anthracene by Introduction of a Methylene Group

A strategy to modulate the mechanical and optical properties of 9,10-dicyanoanthracene (DCA) through subtle structural modification is reported. The cyanomethyl-substituted DCA derivative CCMA forms blue- and green-emitting polymorphs that exhibit face-selective elastic and plastic bending. Crystallographic analyses revealed that intercolumnar interactions along the deformation axis are responsible for the elastic response. Furthermore, the methylene unit suppresses excimer formation, resulting in a shorter-wavelength emission of CCMA, compared to that of DCA in the pristine and ground phases.