Influence of radical initiators in gold catalysis:: Evidence supporting trapping of radicals derived from azobis(isobutyronitrile) by gold halides

Gold halides (AuCl3, HAuCl4, and AuCl) efficiently trap the radicals generated in the room-temperature photolysis of azobis(isobutyronitrile) (AIBN) to give an organogold H[(CH3)(2)CCN](2)AuCl2 compound that has been characterized by spectroscopy. The characteristic features of the organogold are a quaternary carbon at 100 ppm on C-13 NMR and a HR-MS peak with a molecular formula Of C8H13N2AuCl. Catalytic data for cyclohexene aerobic oxidation confirms the beneficial influence of the presence of AlBN on the catalytic activity of Au/CeO2C. (c) 2006 Published by Elsevier Inc.