2024/05/20 by Ryan C. Fortenberry, Brett A. McGuire, Fortenberry, Ryan C. +1 · 1 citation
Engineering · Materials Science · #Advanced ceramic materials synthesis #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Silicon Nanostructures and Photoluminescence #Silicon and Solar Cell Technologies
paper · pdf · doi:10.48550/arxiv.2405.12092
openalex publication_date 2024/05/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The formation of silicon monosulfide (SiS) in space appears to be a difficult process, but the present work is showing that a previously excluded pathway may contribute to its astronomical abundance. Reaction of the radicals SH + SiH produces SiS with a submerged transition state and generates a stabilizing H2 molecule as a product to dissipate the kinetic energy. Such is a textbook chemical reaction for favorable gas-phase chemistry. While previously proposed mechanisms reacting atomic sulfur and silicon with SiH, SH, and H2S will still be major contributors to the production of SiS, an abundance of SiS in certain regions could be a marker for the presence of SiH where it has previously been unobserved. These quantum chemically-computed reaction profiles imply that the silicon-chalcogen chemistry of molecular clouds, shocked regions, or protoplanetary disks may be richer than previously thought. Quantum chemical spectral data for the intermediate cis- and trans-HSiSH are also provided in order to aid in their potential spectroscopic characterization.