Autor: |
Amassah, Georgina, Mitchell, Deborah G., Hovey, Tanden A., Eaton, Sandra S., Eaton, Gareth R. |
Zdroj: |
Applied Magnetic Resonance; Sep2023, Vol. 54 Issue 9, p849-867, 19p |
Abstrakt: |
Electron spin relaxation times are reported for the SO2− radical in solid Na2S2O4 and K2S2O5, and the SO3− radicals in Na2S2O5, and K2S2O5. Echo envelope modulation was observed for the radicals in the Na+ salts and characterized by HYSCORE. Tm and T1 were measured using spin echo methods from 40 to 293 K and by long-pulse saturation recovery at 293 K. At low temperature Tm for the radicals in K2S2O5 (~ 14 μs) is longer than for the radicals in Na2S2O5 (Tm ~ 7 μs) or Na2S2O4 (Tm ~ 4 μs), which is attributed to the low magnetic moment of K+. The shorter value of Tm in Na2S2O4 is attributed in part to higher spin concentration. Tm decreases with increasing temperature as T1 approaches Tm. In each lattice there is a distribution of spin lattice relaxation times that may be due to distributions in interspin distances. The long components in the T1 distributions are longer for SO3− than for SO2−. In 0.5 M NaOH solution at 293 K SO2− has a relaxation-determined Lorentzian peak-to-peak linewidth of about 0.7 G, and T1 ~ T2 ~ 100 ns. [ABSTRACT FROM AUTHOR] |
Databáze: |
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