Elizaveta V. Saenko

Communication: Stabilization of radical anions with weakly bound electron in condensed media: A case study of diacetonyl radical anion

The radical anion resulting from electron capture by diacetonyl molecule has been characterized by EPR and optical absorption spectroscopy in glassy ether matrices at 77 K. In non-polar alkane glasses this species was not observed under the same conditions, which confirms the crucial role of matrix interactions in stabilizing this species. Calculations at the MP2 level show the vertical detachment energy to increase gradually from roughly zero for a bare anion to ∼1 eV for the complex involving six ether molecules.

Radiation-induced transformations of methanol molecules in low-temperature solids: a matrix isolation study

The effect of X-ray irradiation on methanol molecules (CH3OH, CD3OH, and 13CH3OH) isolated in solid noble gas matrices (Ne, Ar, Kr, and Xe) was studied by FTIR spectroscopy at 6 K. CH2OH˙, H2CO, HCO˙ and CO were found to be the main degradation products. Somewhat unexpectedly, the production of CO is quite prominent, even at low doses, and it strongly predominates in low-polarizable matrices (especially, in neon). This result is explained by inefficient quenching of excess energy in the H2CO molecules initially generated from methanol. Relatively small amounts of CH4, CH3˙ and CO2 were also observed directly after irradiation. The latter species presumably originates from methanol dimers or methanol-water complexes. The mechanisms of radiolysis and annealing-induced reactions are discussed and possible implications for the astrochemically relevant ices are considered.