Hydrated electron, reactions

Hydrated electrons, reactions of, with organic compounds, 7, 115... 

How does structure determine organic reactivity, 35, 67 Hydrated electrons, reactions of, with organic compounds, 7,115 Hydration, reversible, of carbonyl compounds, 4, 1 Hydride shifts and transfers, 24, 57... 

The measured H atom G-value is about 0.25 at MZ jE = 1, while the equivalent yield of hydrated electrons is found at MZ jE = 10. The persistence of the hydrated electron to higher MZ jE values suggests that it does not decrease to zero at an infinite value of MZ jE. Most H atoms are produced in conjunction with OH radicals in the core of the heavy ion track. The recombination rate constant is high so there is a small probability that H atoms will escape the track at high LET (MZ jE). H atoms can be formed by hydrated electron reactions and their yield cannot decrease to zero if hydrated electron yields do not. However, hydrated electron yields are low at high MZ /E values so the H atom yield can be considered negligible in this region. 

Hart, E.J., Sheffield, G., and Thomas, J.K., Rate constants of hydrated electron reactions with organic compounds, ]. Phys. Chem., 68(6), 1271-1274, 1964. 

Hydrated-electron reactions are, by definition, electron-transfer processes, which are not very common in classical organic chemistry. The kinetic studies have shown, however, that the eleotron behaves analogously to a classical nucleophilic reagent and, although this analogy... 

There has been a tendency among radiation chemists to use the information on the kinetic and stoicheiometric behaviour of dilute aqueous solutions containing biochemical solutes for interpreting mechanisms of molecular radiobiology. Such a comparison may possibly be justified for the reactions of OH radicals and H atoms. The analogous treatment of hydrated-electron reactions seems, however, to be a gross oversimplification that might easily result in erroneous conclusions. 

In the following paragraphs, we shall describe the known information on the reactivity of different constituents of the living cell with hydrated electrons, bearing in mind that the information described does not represent part of the mechanism of radiobiological damage. Hydrated-electron reactions may, therefore, be used in molecular radiobiology, with appropriate caution, merely as model processes for electron-transfer reactions which undoubtedly take place in the radiolysed cell. 

It has been demonstrated that hydrated-electron reactions invariably proceed by the transfer of an electron from its site in the solvent into a vacancy in the acceptor molecule, irrespective of the charge of the latter... 

How does structure determine organic reactivity, 35, 67 Hydrated electrons, reactions of, with organic compounds, 7,1 15 Hydration, reversible, of carbonyl compounds, 4, 1 Hydride shifts and transfers, 24, 57 Hydrocarbons, small-ring, gas-phase pyrolysis of, 4, 147 Hydrogen atom abstraction from O—H bonds, 9, 127 Hydrogen bonding and chemical reactivity, 26, 255 Hydrogen isotope effects in aromatic substitution reactions. 2, 163... 

The measurement and identification of the hydrated-electron spectrum led to a major increase in activity. It was now possible to directly measure the rate of hydrated-electron reactions with a large variety of inorganic and organic species. With these data, it was then possible to classify reactions in ways that had not been possible previously. It was possible to show that some reactions were diffusion controlled and to suggest that there were some reactions that were even faster than diffusion controlled (at least if one assumed normal reaction radii). Conductivity measurements could directly measure the mobility of ions and could provide information that was unavailable in other ways. ... 

Braams R. (1966) Rate constants of hydrated electron reactions with amino acids. Radiat Res 27 319-329. 

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