Excitation (total ion yield) and de-excitation (resonant photoemission) spectra have been measured in the Si 1s photoexcitation region of the F(3)SiCH(2)CH(2)Si(CH(3))(3) molecule using monochromatized undulator radiation. Theoretical calculations within the framework of density functional theory have reproduced the observed total ion yield spectrum very well. The first peak at the lowest photon energy, coming from Si 1s excitation at the trimethyl side into a vacant orbital, induces spectator Auger decays in which the excited electron remains in its valence orbital. The second peak produced through excitation of Si 1s electron at the trifluoride side generates resonant Auger decays in which the excited valence electron remains predominantly also in the valence orbital or is partly shaken up into higher Rydberg orbitals. The third peak generated through Si 1s excitation at the trifluoride side produces resonant Auger decays in which the excited Rydberg electron remains or is partly shaken down to a lower lying valence molecular orbital. These findings exhibit a clear distinction between resonant Auger decays following photoexcitation of Si 1s electrons under different chemical environments.

Recycling reactions of natural vitamin E (a-tocopherol) by catechins contained in green tea were studied with a double-mixing stopped-flow spectrophotometer. The second-order reaction rate constants of the catechins and deuterated analogues were determined by using a simulation, the activation energies were obtained from the temperature dependences, and the deuterium kinetic-isotope effects were examined. From these results, a tunneling effect was found to play an important role in the vitamin E recycling reactions by the catechins, and the structure-activity relationship was clarified. Furthermore, conditions under which the tunneling effect manifests itself in various vitamin E recycling reactions in biological systems and foods were suggested. A new a-tocopherol-recycling capacity assay-method was also proposed, and named an ATREC assay-method after the acronym. Scheme 3 (a) Catechol. (b) Pyrogallol. 47332 | RSC Adv., 2016, 6, 47325-47336 This journal is

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