Tunable Solid‐State Thermochromism: Alkyl Chain Length‐Dependent Conformational Isomerization of Bianthrones
Tunable Solid‐State Thermochromism: Alkyl Chain Length‐Dependent Conformational Isomerization of Bianthrones
复制标题
可调固态热致变色：联二酮的烷基链长度依赖性构象异构化
DOI：
10.1002/asia.202200121
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Kubo Takashi
中科院分区：
文献类型：
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作者：
Hirao Yasukazu;Hamamoto Yosuke;Kubo Takashi
直链烷氧基链的引入促进了次要扭曲构象的聚集，并使其在固态下与主要折叠构象竞争。甲氧基和正丁氧基取代的衍生物的快速蒸发方法提供了作为亚稳固体的折叠和扭曲构象异构体的粉末混合物。在加热粉末时，不同长度的烷基链通过固态异构化反应聚集成不同的构象，具有明显的颜色变化。通过FT-IR光谱和粉末XRD监测确保这些异构化反应仅涉及构象异构化而不涉及热解。此外，单晶X射线结构分析表明，具有较长烷基链的扭曲构象通过其链间疏水相互作用和π-π堆积相互作用的协同效应而稳定在固态。
The introduction of linear alkoxy chains into bianthrone promoted the aggregation of the minor twisted conformer and made it compete with the major folded conformer in the solid‐state. Rapid evaporation approach to the methoxy‐ andn‐butoxy‐substituted derivatives provided powder mixtures of folded and twisted conformers as metastable solids. Upon heating the powders, different lengths of alkyl chains converged to different conformers via solid‐state isomerization reaction with an apparent color change. Monitoring by FT‐IR spectroscopy and powder XRD ensured that these isomerization reactions involve only conformational isomerization without pyrolysis. In addition, single crystal X‐ray structure analysis revealed that twisted conformers with longer alkyl chains are stabilized in the solid‐state by the synergistic effect of their inter‐chain hydrophobic interactions and π‐π stacking interactions.