At the crossroad of photochemistry and radiation chemistry: formation of hydroxyl radicals in diluted aqueous solutions exposed to ultraviolet radiation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389021%3A_____%2F17%3A00508701" target="_blank" >RIV/61389021:_____/17:00508701 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/17:00484754 RIV/68407700:21340/17:00317958

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2017/CP/C7CP05125E#!divAbstract" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2017/CP/C7CP05125E#!divAbstract</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c7cp05125e" target="_blank" >10.1039/c7cp05125e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

At the crossroad of photochemistry and radiation chemistry: formation of hydroxyl radicals in diluted aqueous solutions exposed to ultraviolet radiation

Popis výsledku v původním jazyce

Formation yields of center dot OH radicals were precisely determined in aqueous solutions of coumarin-3-carboxylic acid and ferrous sulfate (i.e., Fricke dosimeter) exposed to 253.7 nm radiation delivered from a continuous source. Quantum yield of center dot OH radicals was determined as similar to 0.08, i.e., roughly one out of twelve photons, efficiently absorbed in UV-illuminated solutions, produced one center dot OH radical. Energetically, a water molecule should undergo a correlated action of at least two 4.9 eV photons delivering enough energy for direct H-OH dissociation (5.0-5.4 eV). We suggest a mechanism based on an interaction of two water molecules, both in long-living triplet states. An intermolecular transfer of excitation energy provided a sufficient amount of energy for the dissociation of one water molecule into center dot OH and H center dot radicals. In an aqueous solution of phospholipids, quantum yields of hydroperoxides formed under these irradiation conditions decreased with total effectively absorbed energy (i.e. a dose), similar to the radiation chemical yields obtained during an exposure to ionizing radiation, such as gamma rays from radionuclide sources. Under 253.7 nm irradiation, one center dot OH radical causes a peroxidation of 34 phospholipid molecules. This implicates chain mechanism of the reaction.

Název v anglickém jazyce

At the crossroad of photochemistry and radiation chemistry: formation of hydroxyl radicals in diluted aqueous solutions exposed to ultraviolet radiation

Popis výsledku anglicky

Formation yields of center dot OH radicals were precisely determined in aqueous solutions of coumarin-3-carboxylic acid and ferrous sulfate (i.e., Fricke dosimeter) exposed to 253.7 nm radiation delivered from a continuous source. Quantum yield of center dot OH radicals was determined as similar to 0.08, i.e., roughly one out of twelve photons, efficiently absorbed in UV-illuminated solutions, produced one center dot OH radical. Energetically, a water molecule should undergo a correlated action of at least two 4.9 eV photons delivering enough energy for direct H-OH dissociation (5.0-5.4 eV). We suggest a mechanism based on an interaction of two water molecules, both in long-living triplet states. An intermolecular transfer of excitation energy provided a sufficient amount of energy for the dissociation of one water molecule into center dot OH and H center dot radicals. In an aqueous solution of phospholipids, quantum yields of hydroperoxides formed under these irradiation conditions decreased with total effectively absorbed energy (i.e. a dose), similar to the radiation chemical yields obtained during an exposure to ionizing radiation, such as gamma rays from radionuclide sources. Under 253.7 nm irradiation, one center dot OH radical causes a peroxidation of 34 phospholipid molecules. This implicates chain mechanism of the reaction.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

19

Číslo periodika v rámci svazku

43

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

7

Strana od-do

29402-29408

Kód UT WoS článku

000414773100042

EID výsledku v databázi Scopus

2-s2.0-85033555655