Reaction Mechanisms in Irradiated, Precipitated, and Mesoporous Silica

摘要: A matrix EPR spectroscopy study of the low temperature γ radiolysis precipitated (Zeosil) and mesoporous high surface silica has afforded evidence formation trapped H-atoms, H-atom centers, siloxy radicals ≡Si–O•, anomalous silyl peroxy ≡Si-OO• with reduced g tensor anisotropy, radical-cations (≡Si–O–Si≡)+•, E′ two species from Ge impurity. Coordination peroxyl diamagnetic ≡Si+ centers is proposed tested by DFT computations in order to justify observed tensor. H-atoms also for structure as an alternative model not requiring intervention Ge, Sn, or CO impurities. The method been employed assess electronic its similarity that carbon radical-cation analogues; results have prompted a revision structures literature ST1 ST2 centers. comparison between type...