ИСТИНА

The chemical evolution of molecules in space is essentially induced by solar and galactic radiation, which make it possible to initiate the reactions in cold astrochemical media, including diffuse interstellar molecular clouds, cometary and planetary ices. Matrix isolation is a useful tool to simulate possible reaction channels for the key relevant molecules under the conditions of extremely low temperatures (down to 5 – 10 K). Two important features of such processes are inefficient relaxation of excess energy and strong effect of weak intermolecular interactions in the frozen environment. On the one hand, it implies large contribution of “hot” reaction channels occurring through vibrationally excited states (somewhat resembling the gas-phase radiation chemistry) ), and, on the other hand it means unique sensitivity of the high-energy processes to subtle effects, which is the feature of the solid-phase radiation chemistry under the conditions of restricted molecular motion. This presentation gives an overview of recent model studies on the radiation-induced degradation and reactions of a number of small molecules presenting interest for astrochemistry and atmospheric chemistry (such as H2O, CO2, CH3OH, C2H5OH, C2H2, HCN, simple freons) carried out in our laboratory