Soot inception: A DFT study of σ and π dimerization of resonantly stabilized aromatic radicals

摘要: Abstract Recent advances in the soot studies have shown experimental evidences of π-radicals and cross-linked structures among molecular constituents just-nucleated particles. could an important role particle nucleation by increasing binding energy between polycyclic aromatic hydrocarbons with respect to pure van der Waals interactions. In this work we use density functional theory Grimme D3 dispersion correction (DFT-D3) hybrid localized Gaussian basis set (B3LYP/6-31G**) analyze classify clustering behaviors two radicals visualized experimentally atomic force microscopy (Commodo et al. Combust. Flame 205: 154–164, 2019). These different topological delocalization unpaired electron. The bandgap characteristics clusters are calculated. theoretical results show a behavior for radicals. one partial localization electron tends form σ-dimer; conversely, radical greater leads π-stacking formation slight overbinding few kcal mol−1 interactions marked lowering bandgap. induced delocalized part explain some spectroscopic observed during nucleation.