Photochemistry of benzene (C6H6) hydrogen cyanide (HCN) co-condensed ices part 1: A source of solid-state production of volatile nitrile compounds in Titan's stratosphere

Formation of c-C6H5CN Ice Using the SPACE TIGER Experimental Setup

“…Ice formation of c-C 6 H 5 CN in the laboratory was recently reported under conditions similar to those found in Titan's atmosphere (Mouzay et al 2021). The experimental results presented in Sections 3.1 and 3.3 show that formation of c-C 6 H 5 CN in the solid phase is also possible under the conditions found in the interior of the cold, dense clouds in the ISM, where the ice mantles at very low temperatures containing c-C 6 H 6 and a molecule with the cyano (C≡N) group (in this case, CH 3 CN) could be exposed to secondary electrons (Bennett et al 2005) or UV photons (Shen et al 2004).…”

“…The subsequent evolution of these ice mantles is characterized by a rich chemistry induced by their energetic processing, which is driven by the secondary keV electrons and the secondary UV field arising from the interaction of the cosmic rays with the ice molecules (Bennett et al 2005), or the gas-phase H 2 molecules (Cecchi-Pestellini & Aiello 1992; Shen et al 2004), respectively. Recent experimental simulations have revealed that photoprocessing of c-C 6 H 6 :HCN ice mixtures with λ > 200 nm UV photons leads to the formation of several nitriles, including c-C 6 H 5 CN (Mouzay et al 2021). Here, we have expanded on this work and tested the solid-state formation of c-C 6 H 5 CN upon energetic processing with both Lyα (λ = 121.2 nm) vacuum ultraviolet (VUV) photons and 2 keV electrons of ice samples containing c-C 6 H 6 and acetonitrile (CH 3 CN), at low temperatures relevant for dense cloud conditions (∼4−10 K).…”

Benzene Vapor Pressures at Titan Temperatures: First Microbalance Results

“…Some relevant benzene detections include those in meteorites, comets, the atmosphere of Titan, and the interstellar medium (Cernicharo et al 2001;Sephton 2002;Coustenis et al 2003;Schumann et al 2019). A search of the refereed astrochemical literature shows that in roughly the past year alone, at least six papers have appeared with benzene in the title (Mouzay et al 2021a(Mouzay et al , 2021b(Mouzay et al , 2021cDubois et al 2021;Nna-Mvondo & Anderson 2022;. To help understand the chemistry and physics of solid benzene in extraterrestrial environments, such as Titan's atmosphere, here we examine one of the compound's physical properties-its vapor pressure.…”