Kinetics of the cyclopentadienyl + Acetylene, fulvenallene + H, and 1-Ethynylcyclopentadiene + H reactions

Document Type

Article

Publication Date

2-18-2010

Abstract

Quantum chemical methods and statistical reaction rate theory are utilized to examine the kinetics and thermochemistry of three reactions occurring on the C7H7 potential energy surface: cyclopentadienyl (C5H5) + acetylene (C2H2), fulvenallene + H, and 1-ethynylcyclopentadiene + H. These reactions are relevant to the formation of polyaromatic hydrocarbons (PAHs) and the combustion of alkylated aromática. Reaction of the resonantly stabilized C5H 5 radical with C2H2 is an important PAH growth reaction; here we identify several new low-energy pathways connecting these reactants with fulvenallene + H, 1-ethynylcyclopentadiene + H, and the cycloheptatrienyl and benzyl radicals. The chemically activated C 5H5 + C2H2 reaction is shown to form cycloheptatrienyl at low temperatures along with minor amounts of benzyl, which is the current evaluation in the literature. However, at typical, combustion temperatures the C7H6 isomers 1-ethynylcyclopentadiene and fulvenallene are the main products. The fulvenallene + H reaction predominantly forms benzyl (among other C7H7 isomers), whereas the 1-ethynylcyclopentadiene reaction leads to C5H5 + C2H2 and fulvenallene + H as the major products. The resonantly stabilized vinylcyclopentadienyl radical is formed in both C7H6 + H processes and is proposed here as a significant C7H7 combustion intermediate. The reactions described here are believed to account for the C7H6 products observed in cyclopentene combustion, where we suggest they are a mixture of 1-ethynylcyclopentadiene and fulvenallene. The C7H6 + H reactions provide a mechanism for the conversion of 1-ethynylcyclopentadiene to fulvenallene and fulvenallene to benzyl. © 2010 American Chemical Society.

Identifier

77649101854 (Scopus)

Publication Title

Journal of Physical Chemistry A

External Full Text Location

https://doi.org/10.1021/jp906835w

e-ISSN

15205215

ISSN

10895639

PubMed ID

20104927

First Page

2275

Last Page

2283

Issue

6

Volume

114

This document is currently not available here.

Share

COinS