Emergence of thermoresponsive and reversible color changes at low temperature is a challenging target. In general, it is not easy to induce sufficient dynamic motion of rigid molecules including chromophore at a lower temperature. The present work shows unusually low‐temperature color‐change properties originating from the dynamic motion of rigid conjugated polymer in solid state. The layered composites of polydiacetylene (PDA) and guest l‐arginine (L‐Arg) (PDA‐(L‐Arg)) exhibit temperature‐responsive gradual color changes with reversibility in the range of 123–333 K in solid crystalline state. The dynamic properties are induced by gradual and reversible distortion of the π‐conjugated main chain in response to temperature. The tuned flexibility of the layered structure facilitates motion of the rigid π‐conjugated molecule at low temperature. The PDA‐(L‐Arg)‐coated substrates are applied to visualization and quantification of 2D and 3D temperature distributions generated by cooling with liquid nitrogen. These thermographic devices afford to image lower temperature range than typical infrared thermography. The present work indicates potentials of layered architectures with tunable flexibility for emergence of dynamic properties.

中文翻译：

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层状结构中共轭聚合物的固态低温热敏性和可逆颜色变化：超越红外热成像技术。

在低温下出现热响应性和可逆颜色变化是一个具有挑战性的目标。通常，在较低温度下诱导包括生色团的刚性分子的充分动态运动并不容易。本工作显示出异常的低温变色特性，其源于固态固态刚性共轭聚合物的动态运动。聚二乙炔（PDA）和客体l的层状复合材料精氨酸（L-Arg）（PDA-（L-Arg））表现出温度响应性的渐变颜色，固态时可逆性在123-333 K范围内。动力学特性是由π共轭主链随温度的逐渐和可逆变形引起的。层状结构的可调柔韧性促进了刚性π共轭分子在低温下的运动。涂有PDA（L-Arg）的基板可用于可视化和量化由液氮冷却产生的2D和3D温度分布。与典型的红外热成像相比，这些热成像设备可提供较低的成像温度范围。目前的工作表明了具有动态性能出现的可调灵活性的分层体系结构的潜力。