Chen Xi, Sakurai Hidehiro, Wang Huan, Gao Simeng, Bi Hong-Da, Bai Fu-Quan
College of Chemistry and Chemical Engineering, Northeast Petroleum University, Daqing, 163318, China.
Phys Chem Chem Phys. 2021 Feb 28;23(8):4681-4689. doi: 10.1039/d0cp06102f. Epub 2021 Feb 17.
Computational analyses of the solid-state properties of triazasumanene (TAS), a C-symmetric nitrogen-doped sumanene derivative, were carried out in this work. The present studies are mainly divided into two parts. In the first part, we demonstrated the differences in the interactions of the crystal packing between the racemic and the homochiral structures: the former having perpendicular columnar packing and the latter forming slipped helical packing. Two geometries of the TAS monomer, a theoretically optimized structure under vacuum and an X-ray crystal structure in experiment, were compared. It can be found that it is not the total interaction energy, but the local interactions (mainly the electrostatic interactions) of the molecular dimer that dominate the columnar stacking conformation. The second part involves the investigation of the potential charge transport properties of the crystals according to the semiclassical Marcus theory with the hopping mechanism using the simple dimer model. The charge transfer integrals of the two sets of dimers, racemic and homochiral dimer models, were compared as well. The calculation results show that the TAS racemic crystal was predicted to have an advantage of hole transport properties. The perpendicular columnar stacking of the homochiral conformation should essentially have better charge transport properties than the racemic conformation. It is reasonable to employ the simple dimer model built using optimized monomers under vacuum for the purpose of the prediction of the molecular packing conformation by IES calculation and the charge transport properties of the perpendicular columnar-stacking crystal. Our work provides a simple approach to the deep understanding of the structure-property relationship of bowl-shaped molecular systems in theory. It can help to facilitate the design and preparation of heteroatom-doped sumanene derivatives with perpendicular columnar stacking crystals as novel organic semiconductor materials.
本工作对一种C对称氮掺杂苝烯衍生物三氮杂苝烯（TAS）的固态性质进行了计算分析。目前的研究主要分为两部分。在第一部分中，我们展示了外消旋体和纯手性结构在晶体堆积相互作用上的差异：前者具有垂直柱状堆积，而后者形成滑移螺旋堆积。比较了TAS单体的两种几何结构，即理论上在真空下优化的结构和实验中的X射线晶体结构。可以发现，主导柱状堆积构象的不是分子二聚体的总相互作用能，而是局部相互作用（主要是静电相互作用）。第二部分涉及根据半经典马库斯理论，采用简单二聚体模型的跳跃机制研究晶体的潜在电荷传输性质。还比较了两组二聚体，即外消旋二聚体模型和纯手性二聚体模型的电荷转移积分。计算结果表明，预测TAS外消旋晶体具有空穴传输性质的优势。纯手性构象的垂直柱状堆积本质上应该比外消旋构象具有更好的电荷传输性质。为了通过IES计算预测分子堆积构象和垂直柱状堆积晶体的电荷传输性质，采用在真空下使用优化单体构建的简单二聚体模型是合理的。我们的工作提供了一种简单的方法，从理论上深入理解碗状分子体系的结构-性质关系。它有助于促进设计和制备具有垂直柱状堆积晶体的杂原子掺杂苝烯衍生物作为新型有机半导体材料。
