Comprehensive computational automated search of barrierless reactions leading to the formation of benzene and other C<sub>6</sub>-membered rings.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39259783.
- Also identified by DOI 10.1126/sciadv.adq4077 and PMC identifier 11389753.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We present the systematic exploration of various potential energy surfaces for systems with C<sub>6</sub>H<sub>6-<i>x</i></sub> (<i>x</i> = 0, 1, 2, or 3) empirical formula using an automatic search approach. The primary objective of this study is to identify reaction pathways that lead to the creation of benzene, <i>o</i>-benzyne, and other rings. These pathways initiate with a barrierless recombination reaction and involve subsequent isomerization reactions with submerged transition states until the final product is reached. The reported reaction profiles are consistent with the existing conditions in the interstellar medium if the hot complex formed can cool down through radiative relaxation. Recent studies on the deactivation of polyaromatic hydrocarbons (PAHs) support the possibility of these reactions taking place. The C<sub>6</sub>-membered rings are considered precursors of PAHs, and our focus is on identifying pathways originating from the barrierless recombination of reactive molecules known to exist in the interstellar medium, with potential implications in other environments.