Radiation-induced transformations of matrix-isolated ethanol molecules at cryogenic temperatures: an FTIR study.

Ethanol (CHOH) is one of the most common alcohol molecules observed in various space media (molecular clouds, star formation regions, and, highly likely, interstellar ices), where it is exposed to light and ionizing radiation, leading to more complex organic molecules and eventually to the biologically important species. To better understand the radiation-induced evolution of ethanol molecules in icy media, we have examined the transformations of isolated CHOH and CDOH under the action of X-rays and vacuum ultraviolet (VUV) radiation in solid inert matrices (Ne, Ar, Kr, and Xe) at 4.4 K using Fourier transform infrared (FTIR) spectroscopy.

An EPR study on the radiolysis of isolated ethanol molecules in solid argon and xenon: matrix control of radiation-induced generation of radicals in cryogenic media.

This paper addresses the basic question of the impact of a chemically inert environment on the radiation-induced transformations of isolated organic molecules in icy media at cryogenic temperatures with possible implications for astrochemical issues. The radicals produced by X-ray irradiation of isolated ethanol molecules (CHOH and CHCDOH) in solid argon and xenon matrices at 7 K were characterized by electron paramagnetic resonance (EPR) spectroscopy. It was shown that methyl (CH˙) and formyl (HCO˙) radicals resulting from the C-C bond cleavage were mainly produced in the case of solid argon, which was attributed to the significant role of "hot" ionic fragmentation and inefficient energy dissipation to medium.

Radiation-induced transformations of acetaldehyde molecules at cryogenic temperatures: a matrix isolation study.

Acetaldehyde is one of the key small organic molecules involved in astrochemical and atmospheric processes occurring under the action of ionizing and UV radiation. While the UV photochemistry of acetaldehyde is well studied, little is known about the mechanism of processes induced by high-energy radiation. This paper reports the first systematic study on the chemical transformations of CHCHO molecules resulting from X-ray irradiation under the conditions of matrix isolation in different solid noble gases (Ne, Ar, Kr, and Xe) at 5 K.

Radiation-Induced Transformations of CH Molecules in Solid Noble-Gas Matrices: Is Benzene Intrinsically Resistant in Condensed Media?

The radiation resistance of aromatic compounds is one of the key concepts of basic and applied radiation chemistry in condensed phases. Usually, it is attributed to the intrinsic radiation stability of the benzene ring. In this work, we have demonstrated for the first time that the isolated benzene molecules undergo rather efficient radiation-induced degradation in rigid inert media at cryogenic temperatures (comparable to that of aliphatic hydrocarbons), and their stability is essentially determined by the intermolecular relaxation correlating with matrix polarizability.