Twinning Organosuperelasticity in a 4-Nitroanthranilic Acid Solvate Crystal

Mechanical deformation in solvated organic crystals and the intermolecular interactions associated with its deformation behavior are intriguing and demand exploration to understand its significance since the deformation has an effect in altering the physical properties of the compound. Herein, we report the finding of superelastic deformation in a solvated organic crystal for the first time. The dioxane solvate of 4-nitroanthranilic acid exhibited superelasticity on application of shear stress. The superelasticity was confirmed quantitatively by the hysteresis loop of the stress–strain curve. Crystallographic studies revealed that mechanical twinning was responsible for the deformation. Interestingly, the strong hydrogen bonding N–H···O and O–H···O interactions in the crystal lattice contributed to the maintenance of the solvated crystal structure during the mechanical stress, while the weak N–H···O interaction was attributed to the flexibility in the structure. These findings unveiled new possibilities to play with intermolecular interactions for designing next-generation flexible organic crystals.