Geniman, M.P.; Morozova, O.B.; Lukzen, N.N.; Grampp, G.; Yurkovskaya, A.V. Marcus Cross-Relationship Probed by Time-Resolved CIDNP. Int. J. Mol. Sci.2023, 24, 13860.
Geniman, M.P.; Morozova, O.B.; Lukzen, N.N.; Grampp, G.; Yurkovskaya, A.V. Marcus Cross-Relationship Probed by Time-Resolved CIDNP. Int. J. Mol. Sci. 2023, 24, 13860.
Geniman, M.P.; Morozova, O.B.; Lukzen, N.N.; Grampp, G.; Yurkovskaya, A.V. Marcus Cross-Relationship Probed by Time-Resolved CIDNP. Int. J. Mol. Sci.2023, 24, 13860.
Geniman, M.P.; Morozova, O.B.; Lukzen, N.N.; Grampp, G.; Yurkovskaya, A.V. Marcus Cross-Relationship Probed by Time-Resolved CIDNP. Int. J. Mol. Sci. 2023, 24, 13860.
Abstract
The time-resolved CIDNP method can provide information about degenerate exchange reactions (DEE) involving short-lived radicals. In the temperature range from 8 to 65°C, the DEE reactions of the guanosine-5’-monophosphate anion GMP(-H)- with the neutral radical GMP(-H)•, of the N-acetyl tyrosine anion NacTyrO- with a neutral radical NacTyrO• and of the tyrosine anion TyrO- with a neutral radical TyrO• were studied. In all the studied cases, the radicals were formed in the reaction of quenching triplet 2,2’-dipyridyl. The reorganization energies were obtained from Arrhenius plots. The rate constant of the reductive electron-transfer reaction in pair GMP(-H)•/TyrO- was determined at T = 25°C. Rate constants of GMP(-H)• radical reduction reactions with TyrO- and NacTyrO- anions calculated by the Marcus cross relation differ from the experimental ones by two orders of magnitude. The rate constants of several other electron transfer reactions involving GMP(-H)-/•, NacTyrO-/•, and TyrO-/• pairs calculated by cross relation agree well with the experimental values. The rate of nuclear paramagnetic relaxation was found for the 3,5 and β-protons TyrO• and NacTyrO•, the 8-proton GMP(-H)• the 3,4-protons DPH• at each temperature. In all cases, the dependences of the rate of nuclear paramagnetic relaxation on temperature are described by the Arrhenius dependence.
Keywords
Chemically induced nuclear polarization (CIDNP); guanosine monophosphate; tyrosine anion; short-lived radicals; degenerate electronic exchange; Marcus theory
Subject
Chemistry and Materials Science, Physical Chemistry
Copyright:
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