MECHANISM OF SO2 ADSORPTION ON RECEPTOR-SITES INCORPORATED INTO POROUS SIO2-FILMS

SO2 adsorption on porous SiO2 films containing alkylamine sites is con sidered. Alkylamine-SO2 complexes are modeled using the molecular mech anics method; it is demonstrated that the SO2 molecule is adsorbed on the amine-containing group of alkylamine. On the basis of these comput ations, the alkylamine fragment responsible for SO2 adsorption was det ermined, and quantum chemical calculations of the electronic structure and complexation energies depending on the number of ethyl substituen ts in the alkylamine were performed. The dipole moment of the alkylami ne-SO2 complex is shown to differ strongly in its magnitude from the g eometric sum of dipole moments of component molecules. The reasons for the difference are charge transfer to SO2 and charge redistribution i n the alkylamine with decreasing electron density on hydrogen atoms.