Mechanism and efficiency of photochemical transformation of ≡SiNNO• radicals grafted to activated Aerosil surface: Calculation of potential energy surface elements for the lower excited state of the radical

Abstract

Assignment of the bands in the optical absorption spectrum of ≡SiNNO• radicals grafted to activated Aerosil surface was performed. A photochemical transformation mechanism was proposed, and the quantum yields of the reaction of ≡SiNNO• radicals relevant to the long-wavelength absorption band at 77 K were determined in the absence and presence of adsorbed CO2 and SF6 on the surface. For the model radical F3SiNNO•, the parameters characterizing the equilibrium geometry of excited states and the geometry of transition states involved in the reaction were determined by quantum-chemical calculations.