Elucidating the Reactivity of O2 (a 1Δg): A Study with Amino Acid Anions and Related Sulfur and Oxygen Anionic Species
| Autor: | Veronica M. Bierbaum, Nicole Eyet, Zhe-Chen Wang |
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| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 123:2586-2591 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/acs.jpca.9b00377 |
| Popis: | Rate constants and product ions were determined for a series of anions reacting with singlet molecular oxygen O2 (a 1Δg) at thermal energy using an electrospray ionization-selected ion flow tube. The 20 naturally occurring amino acids were used to produce corresponding deprotonated anions; only [Cys-H]− and [Pro-H]− were found to be reactive with O2 (a 1Δg), generating OSCH2CH(NH2)CO2– + HO and C5H6NO2– + H2O2, respectively. The reaction of O2 (a 1Δg) with [Cys-H]− has a rate constant more than ten times larger than the reaction of O2 (a 1Δg) with [Pro-H]−. Furthermore, reactions of O2 (a 1Δg) with carboxylic acid and thiol anions were carried out to elucidate the reactivity of the sulfur-containing functional groups. Potential energy surfaces and overall reaction exothermicities were calculated for representative reactions using density functional theory. Reactions in which attack occurs at the sulfur produce HCSO– as an ionic product. Reactions of several carboxylic acid anions likely proceed through a ... |
| Databáze: | OpenAIRE |
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