Infrared Spectroscopic and Theoretical Studies of the Crystallization of ice films, Dynamics of small Organic Molecules in an Adsorption State on the interface of ice films, and an Interfacial Transport.

FTIR Reflection Absorption spectral technique was applied to the studies of the crystallization and morphological dynamics of the vapor-deposited noncrystalline films of ice and small organic substances of environmental interest.  In particular, by employing simple optical models, i.e. Fresnel approach, to the interpretation of the ice spectra we have concluded that crystallization near 160 K proceeds directly from noncrystalline to crystalline state without any long-lived intermediate state structurally different from its predecessor.  In the case of an acetone deposition, crystallographically oriented growth was observed such that the carbonyl group is nearly parallel to the substrate surface, whereas carbon skeleton is preferentially oriented in the surface-normal direction.    Distinct adsorption and absorption hydrogen-bonded and non-coordinated complexes between acetone, acetaldehyde, and methanol and water network were detected spectrally, and their tentative topological structures are suggested based on MP2 and DFT calculations.  In the case of carbonyl compounds, the formation of guest-ice complexes with single and double hydrogen bonds was clearly shown.  The experimental and computational results indicate that the cooperative effect is evident and very strong in the hydrogen-bonded network systems.    Classical molecular dynamic studies of a near-surface region of the basal surface of the hexagonal ice revealed a noticeable dynamic disorder and enhanced interlayer molecular traffic in the top bilayers of the ice structure already at relatively low temperatures.  Both dynamic effects play a pivotal role in the adsorption and interface penetrating processes for van der Waals particles such as Xe and Rn atoms.  Moreover, these studies combined with the IR spectral data appear to provide a useful background for analysis of the surface dynamic and the mechanism of interface penetration by small organic molecules such as acetone and methanol.   An application of the formal kinetic approach within a framework of the Langmuir formalism to the molecular transport across aqueous interfaces can be consolidated with the Hertz-Knudsen kinetic equation, which is widely employed in experimental atmospheric chemistry.  Furthermore, the proposed treatment allows obtaining a useful expression for the mass accommodation coefficient as a function of the interface adsorption capacity and the concentrations of a guest in gas and liquid phases.