Aminoferrocene:Determination of the acidity of unstable compounds

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F19%3A00110349" target="_blank" >RIV/00216224:14310/19:00110349 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Aminoferrocene:Determination of the acidity of unstable compounds

Popis výsledku v původním jazyce

Ferrocenes are quite popular in electrochemistry, due to the simplicity of redox reactions of iron core. While ferrocene is nonpolar and thus of limited use, its cyclopentadienyl ring opens way for many interesting modifications. One of which is aminoferrocene (FcNH2), the -NH2 group increases solubility in polar solvents, introduces chemical reactivity and most importantly pH sensitivity to the ferrocene complex. Due to the proximity of NH2 group and Fe2+ ion in FcNH2, the redox potential of FcNH2 is influenced by protonation and vice versa the Fe3+ ion changes acidity of the complex upon oxidation. Electrochemical observation of this interplay can be used to deduce the acidity of the Fe3+ complex. Such approach is useful for complexes that are unstable in their oxidized form. pKa constants determined using electrochemical methods are obtained through kinetic processes, therefore great care needs to be taken when interpreting these results. While the limiting redox potential for FcNH2 is easily obtained from electrochemical results (Figure), the limiting potential for FcNH3+ strongly varies depending on the type of electrode used. This is anomalous from other ferrocene derivates, namely ferroceneboronic acid [1] and ferrocenecarboxylic acid [2], where both limiting redox potentials are easily obtainable. In our contribution, we tried to uncover the correct pKa value of aminoferrocene through different electrochemical methods both in buffered and unbuffered solutions. Spectrophotometry was used along to validate our findings.

Název v anglickém jazyce

Aminoferrocene:Determination of the acidity of unstable compounds

Popis výsledku anglicky

Ferrocenes are quite popular in electrochemistry, due to the simplicity of redox reactions of iron core. While ferrocene is nonpolar and thus of limited use, its cyclopentadienyl ring opens way for many interesting modifications. One of which is aminoferrocene (FcNH2), the -NH2 group increases solubility in polar solvents, introduces chemical reactivity and most importantly pH sensitivity to the ferrocene complex. Due to the proximity of NH2 group and Fe2+ ion in FcNH2, the redox potential of FcNH2 is influenced by protonation and vice versa the Fe3+ ion changes acidity of the complex upon oxidation. Electrochemical observation of this interplay can be used to deduce the acidity of the Fe3+ complex. Such approach is useful for complexes that are unstable in their oxidized form. pKa constants determined using electrochemical methods are obtained through kinetic processes, therefore great care needs to be taken when interpreting these results. While the limiting redox potential for FcNH2 is easily obtained from electrochemical results (Figure), the limiting potential for FcNH3+ strongly varies depending on the type of electrode used. This is anomalous from other ferrocene derivates, namely ferroceneboronic acid [1] and ferrocenecarboxylic acid [2], where both limiting redox potentials are easily obtainable. In our contribution, we tried to uncover the correct pKa value of aminoferrocene through different electrochemical methods both in buffered and unbuffered solutions. Spectrophotometry was used along to validate our findings.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10405 - Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)

Projekt

<a href="/cs/project/LQ1601" target="_blank" >LQ1601: CEITEC 2020</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

XIX. Workshop of Biophysical Chemists and Electrochemists

ISBN

9788021093096

ISSN

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e-ISSN

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Počet stran výsledku

2

Strana od-do

34-35

Název nakladatele

Masarykova univerzita

Místo vydání

Brno

Místo konání akce

Brno

Datum konání akce

14. 6. 2019

Typ akce podle státní příslušnosti

EUR - Evropská akce

Kód UT WoS článku

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