Sublimation and infrared spectral properties of ammonium cyanide

Data from Perry A. Gerakines, Yukiko Y. Yarnall, Reggie L. Hudson,Sublimation and infrared spectral properties of ammonium cyanide,Icarus,Volume 413,2024,116007,ISSN 0019-1035,https://doi.org/10.1016/j.icarus.2024.116007.(https://www.sciencedirect.com/science/article/pii/S0019103524000654)Abstract: The ammonium ion (NH4+) has been suggested to be present in interstellar ices and has been observed on the surfaces of planetary bodies using infrared (IR) spectroscopy as the primary means of identification. Evidence for several ammonium salts has also been found in the dust and surface ices of comet 67P/Churyumov-Gerasimenko. Here we present a laboratory study of ammonium cyanide (NH4CN) and report on several properties of this compound, measured with higher accuracy than in previous reports, including its IR band strengths and optical constants for use in quantifying its abundance in interstellar and planetary ices. We also report the first measurements since 1882 of NH4CN vapor pressures, sublimation fluxes, and sublimation enthalpy measured at temperatures relevant to subliming cometary ices (134–155 K). The density and refractive index of NH4CN at 125 K and the sublimation enthalpy and vapor pressures of NH3 at ~100 K are also reported. Keywords: Ices; IR spectroscopy; Comets; Infrared observations This work was funded by the NASA Astrophysics Research and Analysis (APRA) and Planetary Data Archiving, Restoration, and Tools (PDART) Programs, as well as NASA's Planetary Science Division Internal Scientist Funding Program through the Fundamental Laboratory Research (FLaRe) work package at the NASA Goddard Space Flight Center.