An Organic Crystal with High Elasticity at an Ultra‐Low Temperature (77 K) and Shapeability at High Temperatures

Abstract

Organic single crystals with elastic bending capability and potential applications in flexible devices and sensors have been elucidated. Exploring the temperature compatibility of elasticity is essential for defining application boundaries of elastic materials. However, related studies have rarely been reported for elastic organic crystals. Now, an organic crystal displays elasticity even in liquid nitrogen (77 K). The elasticity can be maintained below ca. 150 °C. At higher temperatures, the heat setting property enables us to make various shapes of crystalline fibers based on this single kind of crystal. Through detailed crystallographic analyses and contrast experiments, the mechanisms behind the unusual low‐temperature elasticity and high‐temperature heat setting are disclosed.

An Optical Waveguiding Organic Crystal with Phase-Dependent Elasticity and Thermoplasticity over Wide Temperature Ranges

“…[29][30][31] There are two key limiting factors in expanding the application of flexible organic crystals: single mechanical property and narrow applicable temperature range. 32,33 The flexibility of organic crystals can be categorized into two types: irreversible plastic deformation and reversible elastic deformation. Most of the organic single crystals can only be elastically or plastically deformed, and it is difficult to incorporate two mechanical properties in the same organic crystal because the elastic and plastic deformations require isotropic and anisotropic packing, respectively.…”

“…36 In the reported organic flexible crystals, the research about applicable temperature is rare, and the limited examples concentrate on either low or high temperatures. 11,33,37 Systematic study of crystal flexibility in a wide temperature range from low to high Page 2 of 18 CCS Chemistry 3 temperature is still not disclosed. Therefore, it is of great significance for the application of flexible materials to solve these two limitations.…”

How Do Molecular Motions Affect Structures and Properties at Molecule and Aggregate Levels?

“…It is well known that organic crystalline materials are commonly rigid and brittle, and they usually crack, shatter or deform irreversibly under external stimuli. [28][29][30][31][32][33] Although the elastic organic crystals have been sporadically reported, [34][35][36][37][38][39][40][41] the MSP relationship of the elastic AIEgen crystals is another interesting issue without systematic research. On the contrary, PhCz and PyCz broke easily in the presence of external force even though PyCz had a similar molecular conformation as ClPyCz (Figure S17).…”

A 47-year-old misunderstanding: Indomethacin Polymorph δ revealed to be two plastically bendable crystal forms by 3D electron diffraction

“…Most plastically bendable molecular crystals were reported at room temperature, while only limited systems were studied above or below room temperature. [61] Because both melt and solution δ-IDM exhibit plastic flexibility at a high temperature (120 °C), the dependence of mechanical properties of IDM polymorphs on temperature is worthy of further investigation.…”