原子-分子碰撞中的绝对碎裂截面：多环芳烃分子非统计碎裂的标度律

Absolute fragmentation cross sections in atom-molecule collisions: scaling laws for non-statistical fragmentation of polycyclic aromatic hydrocarbon molecules.

作者信息

Chen T, Gatchell M, Stockett M H, Alexander J D, Zhang Y, Rousseau P, Domaracka A, Maclot S, Delaunay R, Adoui L, Huber B A, Schlathölter T, Schmidt H T, Cederquist H, Zettergren H

机构信息

Department of Physics, Stockholm University, S-106 91 Stockholm, Sweden.

Department of Mathematics, Faculty of Physics, M. V. Lomonosov Moscow State University, Leninskie Gory, 119991 Moscow, Russia.

出版信息

J Chem Phys. 2014 Jun 14;140(22):224306. doi: 10.1063/1.4881603.

DOI:10.1063/1.4881603

PMID:24929387

Abstract

We present scaling laws for absolute cross sections for non-statistical fragmentation in collisions between Polycyclic Aromatic Hydrocarbons (PAH/PAH(+)) and hydrogen or helium atoms with kinetic energies ranging from 50 eV to 10 keV. Further, we calculate the total fragmentation cross sections (including statistical fragmentation) for 110 eV PAH/PAH(+) + He collisions, and show that they compare well with experimental results. We demonstrate that non-statistical fragmentation becomes dominant for large PAHs and that it yields highly reactive fragments forming strong covalent bonds with atoms (H and N) and molecules (C6H5). Thus nonstatistical fragmentation may be an effective initial step in the formation of, e.g., Polycyclic Aromatic Nitrogen Heterocycles (PANHs). This relates to recent discussions on the evolution of PAHNs in space and the reactivities of defect graphene structures.

摘要

我们给出了多环芳烃（PAH/PAH(+)）与氢或氦原子碰撞时非统计碎片化绝对截面的标度律，碰撞动能范围为50电子伏特至10千电子伏特。此外，我们计算了110电子伏特下PAH/PAH(+) + He碰撞的总碎片化截面（包括统计碎片化），并表明它们与实验结果吻合良好。我们证明，对于大型多环芳烃，非统计碎片化占主导地位，并且它会产生与原子（H和N）和分子（C6H5）形成强共价键的高反应性碎片。因此，非统计碎片化可能是例如多环芳族氮杂环（PANHs）形成过程中的一个有效初始步骤。这与近期关于太空中多环芳族氮杂环的演化以及缺陷石墨烯结构的反应性的讨论相关。