Manifold Mechanical Deformations of Organic Crystals with Optical Waveguiding and Polarization Rotation Functions

Abstract

Although manifold flexible organic crystals with various kinds of mechanical properties have been reported recently, most of them only possess a single one that is either plastic or elastic. It is because different mechanical deformations require distinct packing structures and intermolecular interactions. Given that the organic crystal has an anisotropic physical nature it is possible but challenging to combine multiple mechanical deformation capabilities into one single crystal. Herein, based on a known organic molecule (Z)‐3‐(4‐(dimethylamino)phenyl)‐2‐phenylacrylonitrile (DPPC), a single crystal is obtained that exhibits three different mechanical properties, namely, elastic bending, thermoplastic bending and plastic twisting deformation. Notably, the unique DPPC crystal could serve as a quite good optical waveguiding medium in the straight, elastically bent and thermoplastic bent states. The crystals are also successfully applied for tuning the polarization direction of the light emitting from the crystal, and thus confirm the famous prediction that twisted crystals can tune polarization direction as liquid crystals do proposed by C. Mauguin in 1911. This study not only has scientific significance in guiding flexibility engineering but also provides a model of flexible organic crystals for multifunctional application in optical devices.

Stimuli-responsive flexible organic crystals

“…21, 4b ). 103 When the temperature was below 110 °C, the elasticity of the crystal was well maintained, while the crystal displayed an irreversible bending deformation upon external force at higher temperatures (110–130 °C). High temperatures will lead to the increase of the intermolecular horizontal distance of π-stacked columns, and the weakening of intermolecular interactions, creating increased space for long-range molecular motion.…”

“…158 Since 2018, Zhang's team systematically explored the application of adaptive crystals in the field of optical waveguides based on a series of derivatives of single-benzene, Schiff base compounds, β-diketone derivatives, hydrazone compounds, and anthracene derivatives. 79,88–105 In addition, mechanically reconfigurable organic crystals could also be used for amplifying spontaneous emission and in polarization rotators, which broaden their applications in different scenarios. 31,106–115…”

“…1, 1s ) also has elastic bending and plastic twisting ability. 103 However, the unique crystal can be applied for tuning the polarization direction of the light emitting from the crystal, and also can be used as a good flexible optical waveguide medium.…”

A Low‐Temperature‐Resistant Flexible Organic Crystal with Circularly Polarized Luminescence

“…[19][20][21] The organic crystalline materials are a new class of materials with ordered structure that is retained upon deformation, and this translates into spatial control over their anisotropy rooted in their three-dimensional crystal lattice. [22,23] Such flexible crystals are germane to the next-generation information technology and electronics, and specifically for lightweight and flexible optical waveguides, [24,25] organic solid lasers, [26] and polarization rotators, [27,28] among other applications.…”

A Low‐Temperature‐Resistant Flexible Organic Crystal with Circularly Polarized Luminescence

“…[19][20][21] The organic crystalline materials are a new class of materials with ordered structure that is retained upon deformation, and this translates into spatial control over their anisotropy rooted in their three-dimensional crystal lattice. [22,23] Such flexible crystals are germane to the next-generation information technology and electronics, and specifically for lightweight and flexible optical waveguides, [24,25] organic solid lasers, [26] and polarization rotators, [27,28] among other applications.…”