Regulating Reversible Untwisting and Twisting Motions in Helical Dynamic Molecular Crystals DOI

Xiaodong Qiu,

Lin Chen, Jun Hou

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 17, 2025

Dynamic molecular crystals with a desirable morphology and controllable responses to external stimuli are highly desired but remain challenging. Here, we present new photoactive crystal (MCA) featuring naphthalene backbone linked vinyl structure an asymmetric tail. It can undergo reversible head-to-tail [2 + 2] photodimerization under visible light illumination heating. Helicoidally twisted crystalline fibers be easily prepared by drop-casting MCA ethanol solution onto glass surface. The thread length fiber width regulated changing the solvent evaporation temperature. An untwists upon irradiation twists back mild heating due dissociation of metastable photodimer (d-MCA), enabling reverse transformation. Crystallinity overall helical reserved well during untwisting twisting cycles, allowing multiple repetitions dynamic motions. Under interval excitation continuous heating, perform cyclical untwisting-twisting motions over 200 times for 5 h. amount significantly affects photoresponse, resulting in fully partial twisting, or complete at different dimer fractions. We found that about 10% d-MCA is enough drive circular movements. Higher photoproduct conversion makes prone fatigue lose cyclic responses. Our results provide excellent example fabricating organic soft robotics photoactuators based on spiral

Language: Английский

Regulating Reversible Untwisting and Twisting Motions in Helical Dynamic Molecular Crystals DOI

Xiaodong Qiu,

Lin Chen, Jun Hou

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: April 17, 2025

Dynamic molecular crystals with a desirable morphology and controllable responses to external stimuli are highly desired but remain challenging. Here, we present new photoactive crystal (MCA) featuring naphthalene backbone linked vinyl structure an asymmetric tail. It can undergo reversible head-to-tail [2 + 2] photodimerization under visible light illumination heating. Helicoidally twisted crystalline fibers be easily prepared by drop-casting MCA ethanol solution onto glass surface. The thread length fiber width regulated changing the solvent evaporation temperature. An untwists upon irradiation twists back mild heating due dissociation of metastable photodimer (d-MCA), enabling reverse transformation. Crystallinity overall helical reserved well during untwisting twisting cycles, allowing multiple repetitions dynamic motions. Under interval excitation continuous heating, perform cyclical untwisting-twisting motions over 200 times for 5 h. amount significantly affects photoresponse, resulting in fully partial twisting, or complete at different dimer fractions. We found that about 10% d-MCA is enough drive circular movements. Higher photoproduct conversion makes prone fatigue lose cyclic responses. Our results provide excellent example fabricating organic soft robotics photoactuators based on spiral

Language: Английский

Citations

0