Reduction Potentials of SO3•-, SO5•-, and S4O6•3-Radicals in Aqueous Solution

1999 ◽  
Vol 103 (18) ◽  
pp. 3581-3588 ◽  
Author(s):  
Tomi Nath Das ◽  
Robert E. Huie ◽  
P. Neta
Keyword(s):  
Aqueous Solution ◽  
Reduction Potentials

scholarly journals A Computational Investigation of the Binding of the Selenium Analogues of Ergothioneine and Ovothiol to Cu(I) and Cu(II) and the Effect of Binding on the Redox Potential of the Cu(II)/Cu(I) Redox Couple

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Jacqueline Wiebe ◽  
Vasyl Zaliskyy ◽  
Eric A. C. Bushnell
Keyword(s):  
Aqueous Solution ◽  
Oxidative Damage ◽  
Reduction Potential ◽  
Redox Couple ◽  
Computational Investigation ◽  
Dft Methods ◽  
Reduction Potentials ◽  
Redox Couples ◽  
Concomitant Reduction ◽  
Dilute Aqueous Solution

The complexes formed from the binding of ovoselenol (OSeH) and ergoseloneine (ESeH) to Cu(II) and Cu(I) have been investigated with DFT methods. From the calculated thermodynamics, the binding of OSeH and ESeH to Cu(II) and Cu(I) ions increases the reduction potential for the Cu(II)/Cu(I) redox couple. The calculated reduction potentials for the Cu(II)(OSe)2/Cu(I)(OSeH)3+ and Cu(II)(ESe)2/Cu(I)(ESeH)3+ redox couples were found to be 1.15 V and 1.24 V in a dilute aqueous solution. By combining the half reactions for the oxidation of OSeH to the diselenide OSeSeO with the reduction of Cu(II)(OSe)2 to Cu(I)(OSeH)3+, the calculated EMF was 0.90 V. For the oxidation of ESeH to the diselenide ESeSeE with the concomitant reduction of Cu(II)(ESe)2 to Cu(I)(ESeH)3+, the calculated EMF was 0.67 V. Thus, for both systems, the reduction of Cu(II) to Cu(I) with concomitant formation of either diselenide is thermodynamically favourable, and it is expected that both OSeH and ESeH are suitable for the protection against copper induced oxidative damage. As a result, the inhibition of the recycling of Cu(I) to Cu(II) is thermodynamically favourable in the presence of OSeH and ESeH.

On the Determination and Use of Reduction Potentials of Short-Lived Radicals. A Review

2000 ◽  
Vol 65 (6) ◽  
pp. 829-843 ◽  
Author(s):  
Henning Lund ◽  
Karen Skov ◽  
Steen Uttrup Pedersen ◽  
Torben Lund ◽  
Kim Daasbjerg
Keyword(s):  
Aqueous Solution ◽  
Electron Transfer ◽  
Reaction Mechanisms ◽  
Nucleophilic Attack ◽  
Grignard Reaction ◽  
Hydroxide Ion ◽  
Reduction Sequence ◽  
Reduction Potentials ◽  
Srn1 Reaction

A method, the "competition method", for the determination of reduction potentials and estimation of standard potentials for short-lived radicals is reviewed. Applications of the reduction potentials of radicals as arguments for reaction mechanisms are presented for the Grignard reaction, the photoreduction of ketones with alcohols, and the SRN1 reaction. Reductions induced by hydroxide ions are discussed in more detail, and the classic reaction between nitrosobenzene and hydroxide ion in aqueous solution is used as an example of such a reaction. A nucleophilic attack by hydroxide ion rather than an electron transfer initiates the reduction sequence. A review with 26 references.

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