Bendable and Twistable Crystals of Flufenamic Acid Form III with Bending Mechanofluorochromism Behavior

Mechanical flexible organic crystals with optical properties have attracted increasing research interest, because of their unusual phenomena and broad application prospects. However, achieving both plasticity and luminescent properties in organic crystals is difficult. Here we report a plastic organic crystal, flufenamic acid (FFA) form III crystal, which shows highly plastic bending along (001) face and hand-twistable behavior under applied external force. It also illustrated a unique bending mechanofluorochromism behavior. In summary, the proposed soft single crystal with mechanical induced fluorescence modulation appears to be of interest to the design of future tunable fluorescent materials.