Multiple stimuli-responsive flexible crystal with 2D elastic bending, plastic twisting and photoinduced bending capabilities.

Stimuli-responsive crystals have aroused tremendous interest due to their potential as smart materials. However, endowing mono-component crystals with multiple stimuli-responsive and multifunction properties is still a great challenge. Here, we report an anthracene derivative, 9-anthraldehyde, which can respond to mechanical force and light. It possesses two-dimensional (2D) elastic bending, plastic twisting and photoinduced bending properties. Unusual elastic bending of the plastic twisted crystal was achieved in one crystal. The crystal obtained in this work is a multi-dimensional elastic crystal, which is different from reported twistable materials. To reveal the mechanisms of the properties of 2D elastic bending, plastic twisting and photoinduced bending, nanoindentation tests, energy framework analysis and Hirshfeld surface analysis were used to study the property–structure relationship at the molecular level. It was found that these properties can be ascribed to the unique intermolecular interactions and types of molecular arrangement. [ABSTRACT FROM AUTHOR]