The Role of Intermolecular Hydrogen Bonding and Proton Transfer in Proton-Coupled Electron Transfer
| Autor: | Timothy M. Alligrant, Julio C. Alvarez |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Hydrogen bond
Chemistry Electrochemistry Photochemistry Redox Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound Electron transfer General Energy Pyridine Polymer chemistry Physical and Theoretical Chemistry Proton-coupled electron transfer Acetonitrile Brønsted–Lowry acid–base theory |
| Zdroj: | The Journal of Physical Chemistry C. 115:10797-10805 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp108339k |
| Popis: | An example of proton-coupled electron transfer (PCET) comprised by the electrochemical oxidation of 1,4-hydroquinone (1,4-H2Q) in acetonitrile was studied in the presence of Bronsted bases in acetonitrile. Of the two types of bases studied, the negatively charged carboxylates, trifluoroacetate (TFAC–), benzoate (BZ–), and acetate (AC–), showed hydrogen bonding with 1,4-H2Q, whereas the neutral amines, pyridine (PY) and N,N′-diisopropylethylamine (DIPEA), did not. This difference allowed a unique investigation of the effect of proton transfer on PCET with and without the influence of hydrogen bonding using two bases (TFAC– and PY) with approximately the same pKa (∼12). The study revealed that hydrogen bonding of 1,4-H2Q with the base TFAC– made the half wave redox potential of 1,4-H2Q more negative (easier to oxidize) by 0.186 V with respect to the oxidation in the presence of the same concentration of added PY, which does not hydrogen bond with 1,4-H2Q. Both types of bases studied, carboxylates and amines... |
| Databáze: | OpenAIRE |
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