Počet záznamů: 1
In situ simultaneous electrochemical ESR study of radicals generated from 2,2-dinitroethene-1,1-diamine (FOX-7). Intramolecular chemical exchange resulting in an alternation line-width effect
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SYSNO ASEP 0541203 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název In situ simultaneous electrochemical ESR study of radicals generated from 2,2-dinitroethene-1,1-diamine (FOX-7). Intramolecular chemical exchange resulting in an alternation line-width effect Tvůrce(i) Šimková, Ludmila (UFCH-W) RID, ORCID
Klíma, Jiří (UFCH-W) RID
Lušpai, Karol (UFCH-W) ORCID, RID, SAI
Malček, M. (SK)
Rockenbauer, A. (HU)Číslo článku 106895 Zdroj.dok. Journal of Magnetic Resonance. - : Elsevier - ISSN 1090-7807
Roč. 323, FEB 2021 (2021)Poč.str. 9 s. Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova ESR ; EPR ; Alternating line-width effect ; FOX-7 ; Temperature dependent ESR ; In situ electrochemically generated radical Vědní obor RIV CG - Elektrochemie Obor OECD Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Způsob publikování Omezený přístup Institucionální podpora UFCH-W - RVO:61388955 UT WOS 000615916500002 EID SCOPUS 85098995316 DOI 10.1016/j.jmr.2020.106895 Anotace The molecule of 2,2-dinitroethene-1,1-diamine (FOX-7) is one of the most interesting molecules with multiple redox centres stabilized by push-pull effect. To reveal the detailed mechanism of its electrochemical process radical intermediates formed in the course of its electrochemical reduction in organic aprotic media have been studied by in situ simultaneous electrochemical ESR measurements (SEESR). The radical generated on the second reduction step possesses an alternating line-width (AL) effect in the ESR spectra as a result of intramolecular dynamic processes in the timescale of ESR splitting constants. The spectra measured at different temperatures (230-335 K) were analysed with the help of a fitting program which includes a molecular dynamics. Observed dynamics describes well an asymmetric 2 site exchange model for the whole temperature range. With help of the optimized parameters and quantum chemical calculations this radical has been identified as 2,2-dinitroethane-1-amine-1-imine radical dianion, [(H2N)(HN)C=C(NO2)(2)](2-). The dynamic process responsible for the AL effect consists of mutual turning (changing of dihedral angle) of the both nitro groups, resulting in an intramolecular spin-density (electron) transfer. The dynamic parameters of the process have been established. (C) 2021 Elsevier Inc. All rights reserved. Pracoviště Ústav fyzikální chemie J.Heyrovského Kontakt Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Rok sběru 2022 Elektronická adresa http://hdl.handle.net/11104/0318799
Počet záznamů: 1