Organic Radical Cations and Neutral Radicals Produced by Radiation in Low-Temperature Matrices

Astrochemically Relevant Radicals and Radical–Molecule Complexes: A New Insight from Matrix Isolation

“…In order to realize the full potential of the matrix isolation technique for the studies of the radiation-induced radicals of astrochemical interest, we have to briefly consider common features of the physical and chemical processes occurring under irradiation of matrix-isolated species. They can be represented by the following general scheme [13][14][15]:…”

“…It should be stressed that, in all the cases using high-energy ionizing radiation, the overwhelming majority of primary events are caused by secondary electrons of relatively low energy, so from the chemical point of view, there is no principal difference (for example, it was demonstrated that the product composition is similar for irradiation with 1 MeV electrons and X-rays with effective energy of ca. 20 keV [13,14]). This similarity justifies the application of convenient laboratory X-ray sources for qualitative modeling of the astrochemical processes, which are naturally induced by a wide range of space radiation.…”

“…Organic radical cations remained elusive for several decades because of their high reactivity, even at low temperatures. The breakthrough was achieved in the 1980s, and since that time, a large number of radical cations produced from complex organic molecules was studied by EPR in detail due to the invention of a convenient and simple laboratory technique based on their stabilization in halocarbon (Freon) matrices at moderately low temperatures (typically, 77 K) (several reviews are available [14,[126][127][128]). An overview of EPR studies on moderate-size organic radical cations stabilized in noble gas matrices made in our laboratory was given elsewhere [14,17].…”

Kinetics and mechanism of the radiation-chemical synthesis of krypton hydrides in solid krypton matrices

“…An original complex of close-cycle helium cryostats based on the SHI RDK-101E cryocoolers used in this study was described in more detail elsewhere (Kobzarenko et al, 2012;Feldman, 2013).…”

“…It may imply both excitation transfer and positive hole transfer followed by the ion-electron recombination (more detailed consideration is given elsewhere : Feldman, 1999;Kobzarenko et al, 2012;Feldman, 2013). Anyway, according to the previous studies Tanskanen et al, 2005), the radiolysis of isolated acetylene molecules in a xenon matrix can be described by a two-step scheme Both С 2 Н radical and C 2 …Xe complex were observed in the IR spectra.…”