Photoinduced Ratchet-Like Rotational Motion of Branched Molecular Crystals.
Photoinduced Ratchet-Like Rotational Motion of Branched Molecular Crystals.
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DOI：
10.1002/anie.201511444
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发表时间：
2016-06
影响因子：
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通讯作者：
Lingyang Zhu;R. Al‐Kaysi;C. Bardeen
中科院分区：
文献类型：
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作者：
Lingyang Zhu;R. Al‐Kaysi;C. Bardeen
光机械分子晶体可以经历各种光诱导运动，包括膨胀、弯曲、扭曲和跳跃。使用更复杂的晶体形状可以提供将这些运动转化为有用的工作的方法。为了产生这样的形状，已经使用pH驱动的再沉淀来生长蒽衍生物4-氟蒽羧酸的支化微晶。当用λ=405 nm的光照射这些微晶时，分子间[4+4]光二聚反应驱动各个分支的扭曲和弯曲。这些变形驱动整个晶体的旋转，该旋转可以在多次曝光中重复。这种旋转的幅度和方向因晶体形状的差异而变化，但典型的分支晶体在25次连续照射1秒后经历50°的净旋转。这些晶体进行棘轮式旋转的能力归因于它们的手性形状。
Photomechanical molecular crystals can undergo a variety of light-induced motions, including expansion, bending, twisting, and jumping. The use of more complex crystal shapes may provide ways to turn these motions into useful work. To generate such shapes, pH-driven reprecipitation has been used to grow branched microcrystals of the anthracene derivative 4-fluoroanthracenecarboxylic acid. When these microcrystals are illuminated with light of λ=405 nm, an intermolecular [4+4] photodimerization reaction drives twisting and bending of the individual branches. These deformations drive a rotation of the overall crystal that can be repeated over multiple exposures to light. The magnitude and direction of this rotation vary because of differences in the crystal shape, but a typical branched crystal undergoes a 50° net rotation after 25 consecutive irradiations for 1 s. The ability of these crystals to undergo ratchet-like rotation is attributed to their chiral shape.