In this paper, we consider the impact of polar curved polycyclic aromatic hydrocarbons (cPAH) on the process of soot formation by employing electronic structure calculations to determine the earliest onset of curvature integration and the binding energy of curved homodimers. The earliest (smallest size) onset of curvature integration was found to be a six ring PAH with at least one pentagonal ring. The σ bonding in the presence of pentagons led to curvature, however, the π bonding strongly favored a planar geometry delaying the onset of curvature and therefore the induction of a flexoelectric dipole moment. The binding energies of cPAH dimers were found to be of similar magnitude to flat PAH containing one or two pentagons, with an alignment of the dipole moments vectors. For the more curved structures, steric effects reduced the dispersion interactions to significantly reduce the interaction energy compared with flat PAH. Homogeneous nucleation of cPAH at flame temperatures then appears unlikely, however, significant interactions are expected between chemi-ions and polar cPAH molecules suggesting heterogeneous nucleation should be explored.

在本文中，我们通过采用电子结构计算来确定最早的曲率积分开始和弯曲同二聚体的结合能，来考虑极性弯曲多环芳烃（cPAH）对烟灰形成过程的影响。发现最早（最小尺寸）的曲率积分开始是具有至少一个五边形环的六环PAH。所述σ在五边形的存在下键合导致曲率，然而，π键合强烈地支持了平面几何形状，该几何形状延迟了曲率的开始并因此延迟了挠性电偶极矩的感应。发现cPAH二聚体的结合能与包含一个或两个五边形的平坦PAH具有相似的量级，并且偶极矩矢量对齐。对于更弯曲的结构，与平面PAH相比，空间效应降低了分散相互作用，从而显着降低了相互作用能。cPAH在火焰温度下的均相成核似乎不太可能，但是，化学离子与极性cPAH分子之间存在显着的相互作用，这表明应该探索异质成核。