Center for Polymers and Organic Solids, Department of Chemistry and Biochemistry , University of California, Santa Barbara , Santa Barbara , California 93106 , United States.
Department of Chemical Engineering , University of California, Santa Barbara , Santa Barbara , California 93106 , United States.
J Am Chem Soc. 2019 Apr 3;141(13):5078-5082. doi: 10.1021/jacs.8b13200. Epub 2019 Mar 18.
High-performance organic semiconducting materials are reliant upon subtle changes in structure across different length scales. These morphological features control relevant physical properties and ultimately device performance. By combining in situ NMR spectroscopy and theoretical calculations, the conjugated small molecule TT is shown to exhibit distinct temperature-dependent local structural features that are related to macroscopic properties. Specifically, lamellar and melt states are shown to exhibit different molecular topologies associated with planar and twisted conformations of TT, respectively. This topological transformation offers a novel avenue for molecular design and control of solid-state organization.
高性能有机半导体材料依赖于不同尺度上结构的细微变化。这些形态特征控制着相关的物理性质，并最终影响器件性能。通过结合原位 NMR 光谱和理论计算，我们展示了共轭小分子 TT 表现出明显的温度依赖的局部结构特征，这些特征与宏观性质有关。具体来说，层状和熔体状态分别表现出与 TT 的平面和扭曲构象相关的不同分子拓扑结构。这种拓扑转变为固态组织的分子设计和控制提供了一条新途径。
