Against the background of great attention on linear polymers and covalent organic frameworks, some small-molecule organic compounds have shown great potential as cathodes for sodium-ion batteries due to their high redox potentials and high specific capacity. However, limited by the fact that most of the current theoretical research methods are aimed at organic crystals, it is challenging to reasonably elaborate the sodium storage mechanisms of single-molecule organic compounds. Herein, we conceptualize a novel research approach for such small-molecule organic materials possessing complex structures by taking the benzoquinone-based compound pillar[5]quinone as an example. The redox-active sites for the sodiation process were predicted systematically by multiple quantitative analyses of molecular surfaces. In addition, the reasonable sequences of discharge sites were verified based on factors such as the single-point energy, degree of molecular structure deformation, chemical bonding, molecular orbital energy gaps, etc. Moreover, the theoretical reduction potentials calculated by this approach showed high consistency with the experimental data. These results are expected to inspire the theoretical investigation of the reduction mechanism and redox potential of small-molecule organic materials.

中文翻译：

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分子表面的定量分析：在苯醌基柱状化合物作为正极的钠化机理中的系统应用

在线性聚合物和共价有机骨架受到广泛关注的背景下，一些小分子有机化合物由于其高氧化还原电位和高比容量而显示出作为钠离子电池正极的巨大潜力。然而，受限于目前大多数理论研究方法都针对有机晶体，合理阐述单分子有机化合物的钠储存机制具有挑战性。在此，我们以苯醌基化合物柱[5]醌为例，构想了一种针对具有复杂结构的小分子有机材料的新研究方法。通过对分子表面的多次定量分析，系统地预测了钠化过程的氧化还原活性位点。此外，等等。此外，通过该方法计算的理论还原电位与实验数据具有高度一致性。这些结果有望激发对小分子有机材料的还原机理和氧化还原电位的理论研究。