Distorted Molecular Conformation Enabled Supramolecular Dynamics in Elastic Organic Single Crystals

Abstract The exploration of elastic organic crystals holds excellent significance for modulating the mechanical properties of the crystal lattice and related practical applications. Instead of fabricating classic planar molecules that assemble in typical criss‐cross packing structures in a crystal lattice, this work presents a new dynamic organic crystal (anthracen‐9‐ylmethyl 4‐nitrobenzoate, p NBA ) with non‐planar twisted molecular conformations through supramolecular interactions. A p NBA single crystal exhibits superior mechanical properties with enhanced elasticity, toughness, and deformability (reversible bending >100 cycles, coiling, and twisting), capable of enduring weights over 4500‐fold of its mass. It is revealed that the crystal elasticity can be dynamically regulated with the crystal thickness, ranging from fully elastic to plastic morphing upon mechanical stress. Moreover, single crystals are comparable to commercial optical waveguides and birefringence components with ultralow loss coefficients (532–935 nm) and high birefringence (0.209@546 nm). This work provides new strategies for flexible organics and expands the boundaries of functional crystalline materials.