Nanotechnology

Organic chemistry

Ribbon

Bending

Elasticity (physics)

Luminescence

Composite material

Chemistry

Materials science

Molecule

Optoelectronics

Advanced Optical Materials

The study of elastic organic single crystals becomes a hot research field in the crystal engineering, and elastic bending of needle‐like crystals has been carefully investigated recently. Herein, based on a structurally simple molecule dimethyl 2,5‐diaminoterephthalate (DMDAT), the organic crystals which display not only elastic bending ability but also elastic twisting ability under applied stress are reported. These ribbon‐like DMDAT crystals are fully flexible and can be freely bended and twisted, thus forming any 3D conformation. Moreover, the unique X‐shaped tetrasubstituted benzene structure enables DMDAT crystals to display efficient yellow emission based on a very small π‐system. Taking these advantages, 3D optical waveguide is successfully realized in the DMDAT crystal with a highly twisted 3D belt‐shaped structure, demonstrating the ultimate 3D application of flexible organic bulk crystals.

Flexible Luminescent Organic Bulk Crystal: 2D Elasticity toward 3D Optical Waveguide