Rapid-scan Coherence Signals in X-band EPR Spectra of Semiquinones with Small Hyperfine Splittings
Semiquinone, Rapid-scan coherence, Hyperfine splitting
College of Natual Science and Mathematics, Chemistry and Biochemistry
Rapid-scan EPR signals for semiquinones with very-small well-resolved hyperfine splittings exhibit coherence signals at a time after passing through the EPR line that is proportional to the reciprocal of the hyperfine splitting. Such coherences are a general phenomenon due to constructive interference of the responses to transient excitation of spins by rapid scan of the magnetic field across equally spaced spin packets. Examples are shown for 2,3,5,6-tetramethoxy-1,4-benzosemiquinone with aH = 46 mG for 12 protons and for 2,5-di-t-butyl-1,4-benzosemiquinone with aH = 59 mG for 18 protons.
Copyright held by author or publisher. User is responsible for all copyright compliance.
Elajaili, H., Rinard, G. A., Yu, Z., Mitchell, D. G., Quine, R. W., Eaton, S. S., & Eaton, G. R. (2015). Rapid-scan coherence signals in X-band EPR spectra of semiquinones with small hyperfine splittings. Journal of Magnetic Resonance (1997), 259, 20-23. DOI: 10.1016/j.jmr.2015.07.010.