Electron paramagnetic resonance spectrum of the FCO2 radical isolated in noble gas matrices

The EPR spectra of the fluoroformyloxyl radical FCO(2) isolated in noble gas matrices at temperatures from 5 to 30 K have been investigated. This study provides principal g values and (19)F hyperfine coupling constants of FCO(2) measured in Ar matrices at 5 K, and yields isotropic values at 30 K. A detailed analysis of the coupling parameters obtained from the EPR and a concomitant high resolution spectroscopic MMW study supported by quantum chemical calculations rationalized the fine and hyperfine interactions of this simple fluorooxyl radical.