Spontaneous and photomechanical twisting of a cyanostilbene-based molecular crystal

Abstract

Developing organic molecular crystals with twisted morphology either through spontaneous formation or in response to external stimuli is compelling yet challenging. In this work, we present a cyanostilbene-based molecular crystal,...

Organic Crystal Packing Is Key to Determining the Photomechanical Response

“…The structures obtained after subsequent DFT optimization of these topochemically generated product crystals closely match the experimental photodimer crystal structures . Conceptually similar approaches have been used to help interpret experiments on 2 − and in a few other systems. , …”

Multistimulus-Responsive Cocrystals of Azobenzene Derivatives with Excellent Elastic Deformation Ability

“…1−5 Compared with traditional materials such as polymers and hydrogels, organic crystalline materials are receiving more and more attentions due to their long-range order in structure, high energy transfer efficiency, molecular designability and rich characterizations of microstructures at the molecular level. 6−10 In recent years, researchers have developed various types of organic crystals that can respond to external stimuli such as force, light, and heat by twisting, 11 rolling, 12 jumping, 13,14 switching fluorescence, 15 and splitting. 16 These rich response forms show the potential of stimulus-responsive materials for applications in actuators, 17−19 information storage, 20 sensors, 21 flexible electronics, 22,23 etc.…”

“…Organisms in nature have developed response mechanisms to cope with a wide range of external environmental stimuli over a long period of evolution, such as vines that could sway in the wind, pansies (also known as “temperature grasses”) that could reorient their leaves as the temperature changes, sunflowers that could chase the sun, and so on. Inspired by the extraordinary stimulus-responsive behavior of these natural systems, scientists and engineers have invested a great deal of effort in creating an immense variety of stimulus-responsive smart materials. − Compared with traditional materials such as polymers and hydrogels, organic crystalline materials are receiving more and more attentions due to their long-range order in structure, high energy transfer efficiency, molecular designability and rich characterizations of microstructures at the molecular level. − In recent years, researchers have developed various types of organic crystals that can respond to external stimuli such as force, light, and heat by twisting, rolling, jumping, , switching fluorescence, and splitting . These rich response forms show the potential of stimulus-responsive materials for applications in actuators, − information storage, sensors, flexible electronics, , etc.…”

Bending, Twisting, and Propulsion of Photoreactive Crystals by Controlled Gas Release

“…The deformation or progression in space of such dynamic materials, together with their favorable mechanical compliance, are the cornerstones of advanced soft robots, [1,2] artificial muscles, [3,4] organic electronics, [5] and actuating devices. [6,7] Whereas motility is well known with organic polymers, stimulated dynamic behavior is only emerging with organic crystals, some of which have been recently demonstrated to respond by bending, [8,9] twisting, [10,11] jumping, [12,13] expansion, [14] popping, [15] swimming, [16] and/or "walking" [4,6] when they are affected by light, [17] temperature, [18] pH, [19] guest molecules, [20] or magnetic field. [21] In this line of thought, light-driven actuation is particularly important, as it offers access to remote and accurate control by converting a predetermined amount of photon energy into lattice strain during the underlying chemical processes, [22][23][24][25][26][27][28][29] resulting in a controllable extent of deformation.…”