Dimerization of polycyclic aromatic hydrocarbons in soot nucleation.
A possible pathway of soot nucleation, in which localized π electrons play an important role in binding the polycyclic aromatic hydrocarbon (PAH) molecules having multiradical characteristics to form stable polymer molecules through covalent bonds, is studied using density functional and semiempirical methods. Results show that the number of covalent bonds formed in the dimerization of two identical PAHs is determined by the radical character, and the sites to form bonds are related to the aromaticity of individual six-membered ring structure. It is further shown that the binding energy of dimerization increases linearly with the diradical character in the range relevant to soot nucleation.
Center for Combustion Energy, Tsinghua University , Beijing 100084, China.
Hong-Bo
HB
Zhang
Xiaoqing
X
You
Hongmiao
H
Wang
Chung K
CK
Law
D019281:Dimerization; D004583:Electrons; D005609:Free Radicals / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011789:Quantum Theory; D053260:Soot / Q000737:chemistry*; D013816:Thermodynamics
D005609:Free Radicals; D011084:Polycyclic Aromatic Hydrocarbons; D053260:Soot