Ferroelasticity with a Biased Hysteresis Loop in a Co-Crystal of Pimelic Acid and 1,2-Di(4-pyridyl)ethane

The formation of two-component supramolecular polymers can lead to high supramolecular designability by a combination of different kinds of components in addition to the development of thermal and physical properties. These features are suitable for screening mechanical properties of low molecular crystals. Herein, we demonstrate ferroelasticity in a co-crystal of pimelic acid and 1,2-di(4-pyridyl)ethane, which form a one-dimensional supramolecular polymer by hydrogen bonds in the single crystalline state. The crystal showed a permanent biased ferroelastic hysteresis loop as a mixture of ferroelasticity and superelasticity, which is attributable to multiple crystallographically independent molecules.