EPR study of radicals derived from n-propyl formate

Abstract

Using the TiCl 3H 2O 2 radical-generating method, we have successfully characterized by EPR at ca. 25°C the radicals formed from the substrate n-propyl formate: CH 3CH 2ĊHOCHO, CH 3ĊHCH 2OCHO, and ĊH 2CH 2CH 2OCHO. As expected on the basis of previous studies in our laboratory, the first two radicals showed a long-range formyl-proton coupling and the last one did not. Moreover, the size of the γ- and δ-CH formyl-proton couplings in CH 3CH 2ĊHOCHO and CH 3ĊHCH 2OCHO, respectively, agreed with the dependence of such couplings on radical structure previously predicted for species of types ĊOCHO and ĊCOCHO.