An EPR spin-trap study of the radicals present during the thermolysis of some novel monoperoxycarbonates and peroxydicarbonates

Abstract

EPR spin-trapping experiments have been employed to study the radicals present during the thermolysis of two peroxydicarbonates, bis(4-tert-butylcyclohexyl) peroxydicarbonate (3) and bis(2-ethylhexyl) peroxydicarbonate (4), and two monoperoxycarbonates, OO-tert-butyl O-(2-ethylhexyl) monoperoxycarbonate (5) and OO-tert-butyl O-isopropyl monoperoxycarbonate (6). The appropriate alkoxycarbonyloxyl radical is trapped during the thermolysis of each of the four peroxides and the tert-butoxyl radical during the thermolysis of 5 and 6. The trapping of a range of second generation carbon-centred radicals is also reported. Evidence is presented that some of these carbon-centred radicals are formed via a 1,5 C to O hydrogen shift whilst others are formed by hydrogen atom abstraction from the parent peroxide.