A theoretical study of the reaction of HCO+ with C2H2

✍ Scribed by del R�o, E.; L�pez, R.; Men�ndez, M. I.; Sordo, T. L.

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 213 KB
• Volume: 21
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/(sici)1096-987x(20000115)21:1<35::aid-jcc4>3.0.co;2-6

✦ Synopsis

A theoretical study was performed for the reaction of formyl cation and acetylene to give C 3 H + 3 + O in flames and C 2 H + 3 (nonclassical) + CO, both in flames and in interstellar clouds. The corresponding Potential Energy Surface (PES) was studied at the B3LYP/cc-pVTZ level of theory, and single-point calculations on the B3LYP geometries were carried out at the CCSD(T)/cc-pVTZ level. Our results display a route to propynal evolving energetically under C 2 H + 3 (nonclassical) + CO and, consequently, accessible in interstellar clouds conditions. This route connects the most stable C 3 H 3 O + isomer (C2-protonated propadienone) with a species from which propynal may be produced in a dissociative electron recombination reaction. The reaction channel to produce the C 3 H + 3 + O evolves basically through two TSs and presents an endothermicity of 63.9 kcal/mol at 2000 K. According to our Gibbs energy profiles, the C2-protonated propadienone is the most stable species at low-moderate temperatures and, consequently, could play a certain role in interstellar chemistry. On the contrary, in combustion chemistry conditions (2000 K) the C 2 H + 3 (nonclassical) + CO products are the most thermodynamically favored species.