Deuterated analogues of the free radical trap DEPMPO: synthesis and EPR studies

Abstract

Three analogues of 5-diethoxyphosphoryl-5-methyl-1-pyrroline N-oxide (DEPMPO, 1) labelled with two (1-d₂), five (1-d₅) or seven (1-d₇) ²H were synthesized and used to trap the tert-butylperoxyl radical. The EPR spectra of 1-d₂-OOBu^t and 1-d₇-OOBu^t spin adducts exhibited more straightforward patterns and better signal to noise ratio than those obtained with 1 or 1-d₅. The use of the easily available 1-d₂ as spin trap could help significantly the analysis of the EPR signals when the signal of either superoxide or alkylperoxyl spin adduct is superimposed with the signals of other spin adducts.