Photo-induced molecular growth of benzonitrile in the gas phase

TL;DR

This study demonstrates the ionization and molecular growth of benzonitrile in the gas phase induced by 266nm UV photons, revealing fragmentation and ion-neutral reactions that lead to larger molecules.

Contribution

It provides experimental evidence of benzonitrile ionization and molecular growth via UV irradiation, highlighting processes relevant to astrochemical environments.

Findings

Benzonitrile ionizes under 266nm UV light.

Fragmentation occurs during low-intensity irradiation.

Ion-neutral reactions promote molecular mass growth.

Abstract

Due to the absorption of high energetic ultraviolet (UV) photons by the surface layers of the cold molecular clouds, only low energetic photons are able to penetrate into the inner regions of these clouds. This leads to lower photo-ionization yield of molecules of higher ionization potential in these environments. However, here we have experimentally shown the ionization of Benzonitrile molecule using 266nm (4.66eV) photons. The low intensity and unfocused laser irradiation of benzonitrile molecules results extensive fragmentation. Moreover, the ion-neutral reactions among the cationic fragments and neutral fragments shows promising molecular mass growth.