Radical Trapping by Gold Chlorides Forming Organogold Intermediates

Organogold compounds arising from the trapping of carbon-centered radicals by gold chlorides (AuCl, AuCl3, and HAuCl4) and colloidal gold have been characterized by different spectroscopic techniques. Laser flash photolysis has provided kinetic evidence of the occurrence of radical trapping in the microsecond time scale, while theoretical calculations give the energetics of the elementary steps. The trapping of carbon radicals by gold species observed here may explain why the presence of radical initiators enhance dramatically the activity of gold catalysts for some reactions occurring through radical intermediates.