Che Yuxuan, Perepichka Dmitrii F
Department of Chemistry, McGill University, Montreal, Quebec, H3A 0B8, Canada.
Angew Chem Int Ed Engl. 2021 Jan 18;60(3):1364-1373. doi: 10.1002/anie.202011521. Epub 2020 Nov 12.
Planarity is essential for many organic electronic materials as it maximizes the intramolecular π-orbital overlap and enables efficient intermolecular interactions through π-stacking. We propose a statistical way of quantifying the planarity of a wide range of conjugated systems. The quantification takes into account all torsional conformations and their relative contribution to the overall structural disorder, through a planarity index ⟨cos ϕ⟩. The propensity for planarization and the effect of rotational disorder were examined for a series of commonly used building blocks. The application of the analysis to extended conjugated systems and the correlations between the gas-phase ⟨cos ϕ⟩ and crystallographically observed planarity in the solid state were explored. Our calculations also reveal a previously unrecognized effect of increasing band gap upon planarization for conjugated systems coupling strong electron donor and acceptor units.
平面性对于许多有机电子材料至关重要，因为它能使分子内π轨道重叠最大化，并通过π堆积实现有效的分子间相互作用。我们提出了一种统计方法来量化各种共轭体系的平面性。这种量化通过平面性指数⟨cos ϕ⟩考虑了所有扭转构象及其对整体结构无序的相对贡献。研究了一系列常用结构单元的平面化倾向和旋转无序效应。探讨了该分析方法在扩展共轭体系中的应用以及气相⟨cos ϕ⟩与固态晶体学观测平面性之间的相关性。我们的计算还揭示了对于耦合强电子供体和受体单元的共轭体系，平面化时带隙增加这一先前未被认识到的效应。
