Electron Spin Resonance of a ggr;hyphen;Irradiated Single Crystal of a Hydrogen Peroxidemdash;Urea Addition Compound at 77deg;K

摘要

The ggr;hyphen;irradiated single crystal of an addition compound H2O2middot;CO(NH2)2at 77deg;K exhibited ESR spectra which were attributed to an O2minus;ion radical and an HO2middot; free radical. The measurements were made at 9.21 and 22.4 kMc/sec for various orientations of the crystal in the magnetic field. For most orientations, the spectra of O2minus;and HO2middot; were singlet and doublet, respectively. An isotropic component of the doublet was approximately 11 G. The g values were found to be anisotropic with the principal values:g1=2.0886,g2=2.0084, andg3=2.0009for O2minus;; whileg1=2.0495,g2=2.0081, andg3=2.0018for HO2middot;. There seems to be no report about O2minus;trapped in a molecular crystal so far, and the results were compared with O2minus;in ionic crystal.