Carbonate radical anion — Thermochemistry

2006 ◽  
Vol 84 (12) ◽  
pp. 1614-1619 ◽  
Author(s):  
D A Armstrong ◽  
W L Waltz ◽  
A Rauk
Keyword(s):  
Gas Phase ◽  
Radical Anion ◽  
Strong Acid ◽  
Free Energies ◽  
Isodesmic Reactions ◽  
Carbonate Radical ◽  
Reduction Potentials ◽  
High Level ◽  
Carbonate Radical Anion ◽  
Nitrate Species

High level ab initio calculations along with isodesmic reactions have been used to derive a set of self-consistent free energies of formation for carbonate and nitrate species in the gas phase and in aqueous solution. The results show that HCO3· is a strong acid, pKa = –4.1, and that E°(CO3·–/CO32) = 1.23 ± 0.15 V.Key words: carbonate radical anion, theoretical, thermochemistry, acidity, reduction potentials.

Hydration Leads to Efficient Reactions of the Carbonate Radical Anion with Hydrogen Chloride in the Gas Phase

2016 ◽  
Vol 121 (1) ◽  
pp. 192-197 ◽  
Author(s):  
Wai Kit Tang ◽  
Christian van der Linde ◽  
Chi-Kit Siu ◽  
Martin K. Beyer
Keyword(s):  
Gas Phase ◽  
Hydrogen Chloride ◽  
Radical Anion ◽  
Carbonate Radical ◽  
Carbonate Radical Anion

Reactions of heme proteins with carbonate radical anion

2009 ◽  
Vol 35 (4) ◽  
pp. 401-409 ◽  
Author(s):  
L. Gebicka ◽  
J. Didik ◽  
J. L. Gebicki
Keyword(s):  
Heme Proteins ◽  
Radical Anion ◽  
Carbonate Radical ◽  
Carbonate Radical Anion

scholarly journals Iron Fenton oxidation of 2′-deoxyguanosine in physiological bicarbonate buffer yields products consistent with the reactive oxygen species carbonate radical anion not the hydroxyl radical

2020 ◽  
Vol 56 (68) ◽  
pp. 9779-9782 ◽  
Author(s):  
Aaron M. Fleming ◽  
Cynthia J. Burrows
Keyword(s):  
Reactive Oxygen Species ◽  
Hydroxyl Radical ◽  
Fenton Reaction ◽  
Radical Anion ◽  
Reactive Oxygen ◽  
Fenton Oxidation ◽  
Oxygen Species ◽  
Bicarbonate Buffer ◽  
Carbonate Radical ◽  
Carbonate Radical Anion

Fe(ii)-Fenton reaction in bicarbonate buffer yields CO3˙−, not HO˙, oxidizing 2′-deoxyguanosine to yield 8-oxo-7,8-dihydro-2′-deoxyguanosine with no ribose damage.

The carbonate radical as one-electron oxidant of carbohydrates in alkaline media

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 143-146
Author(s):  
Magnus Carlsson ◽  
David Stenman ◽  
Gábor Merényi ◽  
Torbjörn Reitberger
Keyword(s):  
Electron Transfer ◽  
Formic Acid ◽  
Gluconic Acid ◽  
Radical Anion ◽  
Alkaline Media ◽  
Product Analysis ◽  
Reaction Sequence ◽  
Carbonate Radical ◽  
Carbonate Radical Anion ◽  
Reaction Schemes

Abstract The mechanism by which the carbonate radical anion reacts with D-glucose in alkaline aqueous solutions has been studied by means of γ-radiolysis. From the product analysis it is concluded that the reaction sequence is initiated by a one-electron transfer between the carbonate radical anion and deprotonated D-glucose. In the presence of molecular oxygen, the major, if not only products of this reaction sequence are formic acid, arabinose and gluconic acid and reaction schemes are proposed to account for the observed formation of these products.

Are thermodynamic cycles necessary for continuum solvent calculation of pKas and reduction potentials?

2015 ◽  
Vol 17 (4) ◽  
pp. 2859-2868 ◽  
Author(s):  
Junming Ho
Keyword(s):  
Free Energy ◽  
Gas Phase ◽  
Thermodynamic Cycle ◽  
Free Energies ◽  
Thermodynamic Cycles ◽  
Reduction Potentials ◽  
Reaction Free Energy

Continuum solvent calculations of pKas and reduction potentials usually entail the use of a thermodynamic cycle to express the reaction free energy in terms of gas phase energies and free energies of solvation.

scholarly journals Cu,Zn-superoxide dismutase-driven free radical modifications: copper- and carbonate radical anion-initiated protein radical chemistry

2008 ◽  
Vol 417 (1) ◽  
pp. 341-353 ◽  
Author(s):  
Dario C. Ramirez ◽  
Sandra E. Gomez-Mejiba ◽  
Jean T. Corbett ◽  
Leesa J. Deterding ◽  
Kenneth B. Tomer ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Active Site ◽  
Radical Anion ◽  
Brain Homogenate ◽  
Experimental Conditions ◽  
Carbonate Radical ◽  
Carbonate Radical Anion ◽  
Protein Radicals ◽  
Mouse Brain Homogenate

The understanding of the mechanism, oxidant(s) involved and how and what protein radicals are produced during the reaction of wild-type SOD1 (Cu,Zn-superoxide dismutase) with H2O2 and their fate is incomplete, but a better understanding of the role of this reaction is needed. We have used immuno-spin trapping and MS analysis to study the protein oxidations driven by human (h) and bovine (b) SOD1 when reacting with H2O2 using HSA (human serum albumin) and mBH (mouse brain homogenate) as target models. In order to gain mechanistic information about this reaction, we considered both copper- and CO3•− (carbonate radical anion)-initiated protein oxidation. We chose experimental conditions that clearly separated SOD1-driven oxidation via CO3•− from that initiated by copper released from the SOD1 active site. In the absence of (bi)carbonate, site-specific radical-mediated fragmentation is produced by SOD1 active-site copper. In the presence of (bi)carbonate and DTPA (diethylenetriaminepenta-acetic acid) (to suppress copper chemistry), CO3•− produced distinct radical sites in both SOD1 and HSA, which caused protein aggregation without causing protein fragmentation. The CO3•− produced by the reaction of hSOD1 with H2O2 also produced distinctive DMPO (5,5-dimethylpyrroline-N-oxide) nitrone adduct-positive protein bands in the mBH. Finally, we propose a biochemical mechanism to explain CO3•− production from CO2, enhanced protein radical formation and protection by (bi)carbonate against H2O2-induced fragmentation of the SOD1 active site. Our present study is important for establishing experimental conditions for studying the molecular mechanism and targets of oxidation during the reverse reaction of SOD1 with H2O2; these results are the first step in analysing the critical targets of SOD1-driven oxidation during pathological processes such as neuroinflammation.

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