Low temperature formation of naphthalene and its role in the synthesis of PAHs (polycyclic aromatic hydrocarbons) in the interstellar medium.

ABSTRACT: Polycyclic aromatic hydrocarbons (PAHs) are regarded as key molecules in the astrochemical evolution of the interstellar medium, but the formation mechanism of even their simplest prototype-naphthalene (C(10)H(8))-has remained an open question. Here, we show in a combined crossed beam and theoretical study that naphthalene can be formed in the gas phase via a barrierless and exoergic reaction between the phenyl radical (C(6)H(5)) and vinylacetylene (CH(2) = CH-C ≡ CH) involving a van-der-Waals complex and submerged barrier in the entrance channel. Our finding challenges conventional wisdom that PAH-formation only occurs at high temperatures such as in combustion systems and implies that low temperature chemistry can initiate the synthesis of the very first PAH in the interstellar medium. I

SUBMITTER: Parker DS 

PROVIDER: S-EPMC3252898 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature