On the EPR Emission Spectrum of Transient Naphthosemiquinone Radical

EPR spectrum in emission mode at the low-field hyperfine lines was observed for 1,4-naphthosemiquinone radical formed by the steady-state photolysis of solution of corresponding quinone in ethanol flowing through the cavity. Observed behavior of this spectrum was analyzed by a phenomenological way. The results support the view that the anomalous electron spin polarization is generated in the radical formation process. The conclusion was compared with the results of intermittent photolysis.