Hydrogen, from radiolytic oxidation

Ru(bipy)3 formed in this reaction is reduced by the sacrificial electron donor sodium ethylenediaminetetra-acetic acid, EDTA. Cat is the colloidal catalyst. With platinum, the quantum yield of hydrogenation was 9.9 x 10 . The yield for C H hydrogenation was much lower. However, it could substantially be improv l by using a Pt colloid which was covered by palladium This example demonstrates that complex colloidal metal catalysts may have specific actions. Bimetalic alloys of high specific area often can prepared by radiolytic reduction of metal ions 3.44) Reactions of oxidizing radicals with colloidal metals have been investigated less thoroughly. OH radicals react with colloidal platinum to form a thin oxide layer which increases the optical absorbance in the UV and protects the colloid from further radical attack. Complexed halide atoms, such as Cl , Br, and I, also react... 

Deeble DJ, Schuchmann MN, Steenken S, von Sonntag C (1990) Direct evidence for the formation of thymine radical cations from the reaction of SO/" with thymine derivatives a pulse radiolysis study with optical and conductance detection. J Phys Chem 94 8186-8192 DeFelippis MR, Murthy CP, Faraggi M, Klapper MH (1989) Pulse radiolytic measurement of redox potentials the tyrosine and tryptophan radicals. Biochemistry 28 4847-4853 Delatour T, Douki T, D Ham C, Cadet J (1998) Photosensitization of thymine nucleobase by benzo-phenone through energy transfer, hydrogen abstraction and one-electron oxidation. J Photo-chem Photobiol 44 191-198... 

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