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http://dx.doi.org/10.25673/38550
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DC Field | Value | Language |
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dc.contributor.author | Kohlmann, Tim | - |
dc.contributor.author | Goez, Martin | - |
dc.date.accessioned | 2021-10-04T08:05:03Z | - |
dc.date.available | 2021-10-04T08:05:03Z | - |
dc.date.issued | 2020 | - |
dc.identifier.uri | https://opendata.uni-halle.de//handle/1981185920/38796 | - |
dc.identifier.uri | http://dx.doi.org/10.25673/38550 | - |
dc.description.abstract | We have demonstrated the feasibility and ease of producing quercetin radicals by photoionization with a pulsed 355 nm laser. A conversion efficiency into radicals of 0.4 is routinely achieved throughout the pH range investigated (pH 2–9), and the radical generation is completed within a few ns. No precursor other than the parent compound is needed, and the ionization by-products do not interfere with the further fate of the radicals. With this generation method, we have characterized the quercetin radicals and studied the kinetics of their repairs by co-antioxidants such as ascorbate and 4-aminophenol. Bell-shaped pH dependences of the observed rate constants reflect opposite trends in the availability of the reacting protonation forms of radical and co-antioxidant and even at their maxima mask the much higher true rate constants. Kinetic isotope effects identify the repairs as proton-coupled electron transfers. An examination of which co-antioxidants are capable of repairing the quercetin radicals and which are not confines the bond dissociation energies of quercetin and its monoanion experimentally to 75–77 kcal mol−1 and 72–75 kcal mol−1, a much narrower interval in the case of the former than previously estimated by theoretical calculations. | eng |
dc.description.sponsorship | Publikationsfonds MLU | - |
dc.language.iso | eng | - |
dc.rights.uri | https://creativecommons.org/licenses/by-nc/4.0/ | - |
dc.subject.ddc | 540 | - |
dc.title | Laser access to quercetin radicals and their repair by co-antioxidants | eng |
dc.type | Article | - |
local.versionType | publishedVersion | - |
local.bibliographicCitation.journaltitle | Chemistry - a European journal | - |
local.bibliographicCitation.volume | 26 | - |
local.bibliographicCitation.issue | 72 | - |
local.bibliographicCitation.pagestart | 17428 | - |
local.bibliographicCitation.pageend | 17436 | - |
local.bibliographicCitation.publishername | Wiley-VCH | - |
local.bibliographicCitation.publisherplace | Weinheim | - |
local.bibliographicCitation.doi | 10.1002/chem.202001956 | - |
local.openaccess | true | - |
local.accessrights.dnb | free | - |
Appears in Collections: | Open Access Publikationen der MLU |
Files in This Item:
File | Description | Size | Format | |
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chem.202001956.pdf | 1.32 MB | Adobe PDF | View/Open |