Multifrequency EPR Spectra of Molecular Oxygen in Solid Air

Continuous-wave EPR at 275GHz: Application to high-spin Fe3+ systems

“…At temperatures above 5 K in the g = 2 region six lines due to a manganese impurity could be properly recorded by scanning slowly with a lower modulation amplitude. The resonance at 7.6 T is due to a contamination of the frozen sample solution with molecular oxygen [37]. The origin of the resonance that is observed at 9.6 T in the 5 K spectrum is not known.…”

“…The signal-to-noise ratio for the resonance at 9.7 T (peak to peak) at 25 K is 200. At 4.4 T and 7.6 T resonances due to molecular oxygen are seen [37]. As in the Fe(III)-EDTA spectra, a resonance of unknown origin is observed at 9.6 T in the 5 K spectrum.…”

Multi-frequency and high-field EPR study of manganese(III) protoporphyrin IX reconstituted myoglobin with an S= 2 integer electron spin

“…4A were confirmed to come from the impurities in the sample holder and the sample itself, respectively. These signals were also observed in the absence of the sample and probably originate from a small amount of solid dioxygen (S = 1) [19]. As described in Section 2, despite of the careful evacuation of the sample space to remove the dioxygen, a small amount of dioxygen might still remain in the sample holder.…”

Tunable-frequency high-field electron paramagnetic resonance

“…This allows an easy visual recognition of particular spectral features. The optimal spin Hamiltonian parameters are subsequently best-fitted to the complete two-dimensional dataset of experimental resonances [15], the fitting procedure being now fully automated. This methodology has its roots in antiferromagnetic resonance (AFMR), where particular AFMR modes are also traced in the two-dimensional field-frequency space [16,17].…”