<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE article SYSTEM "http://www.atmos-chem-phys-discuss.net/inc/acpd/copernicus.dtd">
<article language="en">
	<journal>
		<journal_title>Atmospheric Chemistry and Physics Discussions</journal_title>
		<journal_url>www.atmos-chem-phys-discuss.net</journal_url>
		<issn>1680-7367</issn>
		<eissn>1680-7375</eissn>
		<volume_number>9</volume_number>
		<issue_number>2</issue_number>
		<publication_year>2009</publication_year>
	</journal>
	<doi>10.5194/acpd-9-7681-2009</doi>
	<article_url>http://www.atmos-chem-phys-discuss.net/9/7681/2009/</article_url>
	<abstract_html>http://www.atmos-chem-phys-discuss.net/9/7681/2009/acpd-9-7681-2009.html</abstract_html>
	<fulltext_pdf>http://www.atmos-chem-phys-discuss.net/9/7681/2009/acpd-9-7681-2009.pdf</fulltext_pdf>
	<start_page>7681</start_page>
	<end_page>7706</end_page>
	<publication_date>2009-03-24</publication_date>
	<article_title content_type="html">Photoinduced oxidation of sea salt halides by aromatic ketones: a source of  halogenated radicals</article_title>
	<authors>
		<author numeration="1" affiliations="1">
			<name>A. Jammoul</name>
		</author>
		<author numeration="2" affiliations="1">
			<name>S. Dumas</name>
		</author>
		<author numeration="3" affiliations="1">
			<name>B. D&apos;Anna</name>
		</author>
		<author numeration="4" affiliations="1">
			<name>C. George</name>
			<email>christian.george@ircelyon.univ-lyon1.fr</email>
		</author>
	</authors>
	<affiliations>
		<affiliation numeration="1" content_type="html">Université de Lyon, Lyon, 69626, France; Université Lyon 1, Lyon,  69626, France; CNRS, INSU, UMR5256, IRCELYON, Institut de recherches sur la  catalyse et l&apos;environnement de Lyon, Villeurbanne, 69626, France</affiliation>
	</affiliations>
	<abstract content_type="html">The interactions between benzophenone triplet state and halide anion
      species (Cl&lt;sup&gt;&amp;minus;&lt;/sup&gt;, Br&lt;sup&gt;&amp;minus;&lt;/sup&gt; and I&lt;sup&gt;&amp;minus;&lt;/sup&gt;) have been studied by
      laser flash photolysis (at 355 nm) in aqueous solutions at
      room temperature. The decay of the triplet state of benzophenone was
      followed at 525 nm. Triplet lifetime measurements provided rate
      constants, &lt;i&gt;k&lt;sub&gt;q&lt;/sub&gt;&lt;/i&gt; (M&lt;sup&gt;&amp;minus;1&lt;/sup&gt; s&lt;sup&gt;&amp;minus;1&lt;/sup&gt;), close to diffusion
      controlled limit for iodide (~8&amp;times;10&lt;sup&gt;9&lt;/sup&gt; M&lt;sup&gt;&amp;minus;1&lt;/sup&gt; s&lt;sup&gt;&amp;minus;1&lt;/sup&gt;), somewhat less for bromide (~3&amp;times;10&lt;sup&gt;8&lt;/sup&gt; M&lt;sup&gt;&amp;minus;1&lt;/sup&gt; s&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) and much lower for chloride (&amp;gt;10&lt;sup&gt;6&lt;/sup&gt; M&lt;sup&gt;&amp;minus;1&lt;/sup&gt; s&lt;sup&gt;&amp;minus;1&lt;/sup&gt;). The halide (X&lt;sup&gt;&amp;minus;&lt;/sup&gt;) quenches the
      triplet state, and a product, having a transient absorption at
      355 nm and a lifetime much longer than that of the
      benzophenone triplet state, is formed. This transient absorption
      feature matches those of the corresponding radical anion
      (X&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;). We therefore suggest that such reactive quenching can
      be a photosensitized source of halogen in the atmosphere and represents a driving force for the chemical oxidation of the oceanic surface.</abstract>
	<references>
		<reference numeration="1" content_type="text"> Alfassi,~Z B., Harriman,~A., Huie,~R E., Mosseri,~S., and Neta,~P.: The redox potential of the azide/azidyl couple,~J. Phys. Chem., 91, 2120–2122, 1987. </reference>
		<reference numeration="2" content_type="text"> Ariya,~P A., Niki,~H., Harris,~G W., Anlauf,~K G., and Worthy,~D E J.: Polar sunrise experiment 1995: hydrocarbon measurements and tropospheric Cl and Br-atoms chemistry, Atmos. Environ., 33, 931–938, 1999. </reference>
		<reference numeration="3" content_type="text"> Barrie,~L A., Bottenheim,~J W., Schnell,~R C., Crutzen,~P J., and Rasmussen,~R A.: Ozone destruction and photochemical reactions at polar sunrise in the lower Arctic atmosphere, Nature, 334, 138–141, 1988. </reference>
		<reference numeration="4" content_type="text"> Becker,~H.-D., Burgdorff,~C., and Loehmannsroeben,~H.-G.: Intramolecular deactivation of photoexcited anthracenes by aromatic ketones,~J. Photochem. Photobiol. A., 86, 133–139, 1995. </reference>
		<reference numeration="5" content_type="text"> Benitez,~F J., Beltran-Heredia,~J., Acero,~J L., and Pinilla,~M L.: Simultaneous photodegradation and ozonation plus UV radiation of phenolic acids–major pollutants in agro-industrial wastewaters,~J. Chem. Technol. Biotechnol., 70, 253–260, 1997. </reference>
		<reference numeration="6" content_type="text"> Bensasson,~R V. and Gramain,~J C.: Benzophenone triplet properties in acetonitrile and water. Reduction by lactams, J. Chem. Soc., Faraday Trans. 1: Phys. Chem. Cond. Phases, 76, 1800–1810, 1980. </reference>
		<reference numeration="7" content_type="text"> Blanchi,~J P. and Watkins,~A R.: Quenching of triplet benzophenone by electron donors,~J. Chem. Soc., Chem. Commun., 265–266, 1974. </reference>
		<reference numeration="8" content_type="text"> Burget,~D. and Jacques,~P.: Unusual solvent effects on the fluorescence quenching rate constants of a~thioxanthone derivative by $n$-butylamine and isoprene, Chem. Phys. Lett., 291, 207–214, 1998. </reference>
		<reference numeration="9" content_type="text"> Canonica,~S., Hellrung,~B., and Wirz,~J.: Oxidation of Phenols by Triplet Aromatic Ketones in Aqueous Solution,~J. Phys. Chem. A, 104, 1226–1232, 2000. </reference>
		<reference numeration="10" content_type="text"> Canonica,~S., Kohn,~T., Mac,~M., Real,~F J., Wirz,~J., and Von Gunten,~U.: Photosensitizer method to determine rate constants for the reaction of carbonate radical with organic compounds, Environ. Sci. Technol., 39, 9182–9188, 2005. </reference>
		<reference numeration="11" content_type="text"> Canonica,~S., Hellrung,~B., Muller,~P., and Wirz,~J.: Aqueous oxidation of phenylurea herbicides by triplet aromatic ketones, Environ. Sci. Technol. FIELD, 40, 6636–6641, 2006. </reference>
		<reference numeration="12" content_type="text"> Cincinelli,~A., Desideri,~P G., Lepri,~L., Checchini,~L., Del Bubba,~M., and Udisti,~R.: Marine contribution to the chemical composition of coastal and inland Antarctic snow, Int J. Environ. Anal. Chem., 79, 283–299, 2001a. </reference>
		<reference numeration="13" content_type="text"> Cincinelli,~A., Stortini,~A M., Perugini,~M., Checchini,~L., and Lepri,~L.: Organic pollutants in sea-surface microlayer and aerosol in the coastal environment of Leghorn-(Tyrrhenian Sea), Mar. Chem., 76, 77–98, 2001b. </reference>
		<reference numeration="14" content_type="text"> Clifford,~D., Donaldson,~D J., Brigante,~M., D&apos;Anna,~B., and George,~C.: Reactive uptake of ozone by chlorophyll at aqueous surfaces, Environ. Sci. Technol., 42, 1138–1143, 2008. </reference>
		<reference numeration="15" content_type="text"> Das,~P K., Encinas,~M V., and Scaiano,~J C.: Laser flash photolysis study of the reactions of carbonyl triplets with phenols and photochemistry of $p$-hydroxypropiophenone,~J. Am. Chem. Soc., 103, 4154–4162, 1981. </reference>
		<reference numeration="16" content_type="text"> Devonshire,~R. and Weiss,~J J.: Nature of the transient species in the photochemistry of negative ions in aqueous solution,~J. Phys. Chem., 72, 3815–3820, 1968. </reference>
		<reference numeration="17" content_type="text"> Douglas,~P., Waechter,~G., and Mills,~A.: Ionic strength effects on the ground state complexation and triplet state electron transfer reaction between Rose Bengal and methyl viologen, Photochem. Photobiol., 52, 473–479, 1990. </reference>
		<reference numeration="18" content_type="text"> Knipping,~E.M., Lakin,~M J., Foster,~K L., Jungwirth,~P., Tobias,~D J., Gerber,~R B., Dabdub,~D., and Finlayson-Pitts,~B J.: Experiments and simulations of ion-enhanced interfacial chemistry on aqueous NaCl, Aerosols Sci., 288, 301–306, 2000. </reference>
		<reference numeration="19" content_type="text"> Encinas,~M V. and Scaiano,~J C.: Reaction of benzophenone triplets with allylic hydrogens. Laser flash photolysis study,~J. Am. Chem. Soc., 103, 6393–6397, 1981. </reference>
		<reference numeration="20" content_type="text"> Encinas,~M V., Lissi,~E A., and Olea,~A F.: Quenching of triplet benzophenone by vitamins E and C and by sulfur-containing amino acids and peptides, Photochem. Photobiol., 42, 347–352, 1985. </reference>
		<reference numeration="21" content_type="text"> Environmenta,~U N E P.: Environmental effects of ozone depletion and its interactions with climate change: Progress report, Photochem, Photobiol. Sci., 8, 13–22, 2009. </reference>
		<reference numeration="22" content_type="text"> Ershov,~B G., Kelm,~M., Gordeev,~A V., and Janata,~E.: A~pulse radiolysis study of the oxidation of \chemBr^- by Cl2.bul.- in aqueous solution: formation and properties of ClBr.bul, Phys. Chem. Chem. Phys., 4, 1872–1875, 2002. </reference>
		<reference numeration="23" content_type="text"> Ershov,~B G. and Janata,~E.: The reduction of I2 by 1-hydroxyalkyl radicals in aqueous solution. A~pulse radiolysis study, Chem. Phys. Lett., 372, 195–198, 2003. </reference>
		<reference numeration="24" content_type="text"> Finlayson-Pitts,~B J.: The tropospheric chemistry of sea salt: a~molecular-level view of the chemistry of NaCl and NaBr, Chem. Rev., 103, 4801–4822, 2003. </reference>
		<reference numeration="25" content_type="text"> Gilbert,~B C., Stell,~J K., Peet,~W J., and Radford,~K J.: Generation and reactions of the chlorine atom in aqueous solution, J. Chem. Soc., Faraday Trans. 1: Phys. Chem. Cond. Phases, 84, 3319–3330, 1988. </reference>
		<reference numeration="26" content_type="text"> Grewer,~C. and Brauer,~H.-D.: Mechanism of the triplet-state quenching by molecular oxygen in solution,~J. Phys. Chem., 98, 4230–4235, 1994. </reference>
		<reference numeration="27" content_type="text"> Grodkowski,~J. and Neta,~P.: Formation and Reaction of Br.bul.-2 radicals in the ionic liquid methyltributylammonium bis(trifluoromethylsulfonyl)imide and in other solvents, J. Phys. Chem. A, 106, 11130–11134, 2002. </reference>
		<reference numeration="28" content_type="text"> Gutierrez,~M I.: Solvent effect on the physical quenching of singlet molecular oxygen by $p$-quinones, Photochem. Photobiol. Sci., 7, 480–484, 2008. </reference>
		<reference numeration="29" content_type="text"> Haag,~W R., Hoigné,~J R., Gassman,~E., and Braun,~A M.: Singlet oxygen in surface waters – Part I: Furfuryl alcohol as a~trapping agent, Chemosphere, 13, 631–640, 1984. </reference>
		<reference numeration="30" content_type="text"> Hasegawa,~K. and Neta,~P.: Rate constants and mechanisms of reaction of chloride (Cl2-) radicals,~J. Phys. Chem., 82, 854–857, 1978. </reference>
		<reference numeration="31" content_type="text"> Haselbach,~E., Jacques,~P., Pilloud,~D., Suppan,~P., and Vauthey,~E.: Quenching of triplet benzophenone by 1,4-diazabicyclo[2.2.2]octane in acetonitrile revisited,~J. Phys. Chem., 95, 7115–7117, 1991. </reference>
		<reference numeration="32" content_type="text"> Huang,~C.-R. and Shu,~H.-Y.: The reaction kinetics, decomposition pathways and intermediate formations of phenol in ozonation, UV/\chemO_3 and UV/\chemH_2O_2 processes,~J. Hazard. Mater., 41, 47–64, 1995. </reference>
		<reference numeration="33" content_type="text"> Hurley,~J K., Linschitz,~H., and Treinin,~A.: Interaction of halide and pseudohalide ions with triplet benzophenone-4-carboxylate: kinetics and radical yields, J. Phys. Chem., 92, 5151–5159, 1988. </reference>
		<reference numeration="34" content_type="text"> Ivanov,~V., Kutsenova,~A., and Khavina,~E.: Chemical dynamics of radical pairs formed by benzophenone photoreduction in solid polymers, Russian Chemical Bulletin, 54, 1445–1448, 2005. </reference>
		<reference numeration="35" content_type="text"> Jacques,~P., Allonas,~X., Von Raumer,~M., Suppan,~P., and Haselbach,~E.: Quenching of triplet benzophenone by methyl and methoxy benzenes: are triplet exciplexes involved?, J. Photochem. Photobiol. A., 111, 41–45, 1997. </reference>
		<reference numeration="36" content_type="text"> Kajii,~Y., Fujita,~M., Hiratsuka,~H., Obi,~K., Mori,~Y., and Tanaka,~I.: Quenching of triplet benzophenone by 2,4,6-tri-tert-butylphenol and formation of its phenoxy radical,~J. Phys. Chem., 91, 2791–2794, 1987. </reference>
		<reference numeration="37" content_type="text"> Lathioor,~E C., Leigh,~W J., and St. Pierre,~M J.: Geometrical effects on intramolecular quenching of aromatic ketone ($p,p$) triplets by remote phenolic hydrogen abstraction, J. Am. Chem. Soc., 121, 11984–11992, 1999. </reference>
		<reference numeration="38" content_type="text"> Lathioor,~E C. and Leigh,~W J.: Geometric and solvent effects on intramolecular phenolic hydrogen abstraction by carbonyl $n,p*$ and $p,p*$ triplets, Can J. Chem., 79, 1851–1863, 2001. </reference>
		<reference numeration="39" content_type="text"> Leigh,~W J., Lathioor,~E C., and St. Pierre,~M J.: Photoinduced Hydrogen Abstraction from Phenols by Aromatic Ketones. A~New Mechanism for Hydrogen Abstraction by Carbonyl $n,p$ and $p,p$ Triplets,~J. Am. Chem. Soc., 118, 12339–12348, 1996. </reference>
		<reference numeration="40" content_type="text"> Martire,~D O., Rosso,~J A., Bertolotti,~S., Le Roux,~G C., Braun,~A M., and Gonzalez,~M C.: Kinetic study of the reactions of chlorine atoms and Cl2.bul.- radical anions in aqueous solutions. II. Toluene, benzoic acid, and chlorobenzene, J. Phys. Chem. A., 105, 5385–5392, 2001. </reference>
		<reference numeration="41" content_type="text"> Mehrdad,~Z., Noll,~A., Grabner,~E.-W., and Schmidt,~R.: Sensitization of singlet oxygen via encounter complexes and via exciplexes of $pp*$ triplet excited sensitizers and oxygen, Photochem. Photobiol. Sci., 1, 263–269, 2002a. </reference>
		<reference numeration="42" content_type="text"> Mehrdad,~Z., Schweitzer,~C., and Schmidt,~R.: Formation of O2(1Sg+), O2(1Dg), and \hboxO2(3Sg-) during oxygen quenching of $np$ triplet phenyl ketones: the role of charge transfer and sensitizer-oxygen complex structure, J. Phys. Chem. A., 106, 228–235, 2002b. </reference>
		<reference numeration="43" content_type="text"> Morrison,~M E., Dorfman,~R C., and Webber,~S E.: Fluorescence quenching kinetics of phenanthrene covalently bound to sodium poly(acrylate-co-acrylamide): effects of ionic strength and counterion, J. Phys. Chem., 100, 15187–15197, 1996. </reference>
		<reference numeration="44" content_type="text"> Murov,~S L., Carmichael,~I., and Hug,~G L.: Handbook of Photochemistry, 2nd edn., Marcel Dekker Inc, New York, 1993. </reference>
		<reference numeration="45" content_type="text"> Oum,~K W., Lakin,~M J., DeHaan,~D O., Brauers,~T., and Finlayson-Pitts,~B J.: Formation of molecular chlorine from the photolysis of ozone and aqueous sea-salt particles, Science (Washington, DC), 279, 74–77, 1998. </reference>
		<reference numeration="46" content_type="text"> Poznyak,~T. and Vivero,~J.: Degradation of aqueous phenol and chlorinated phenols by ozone, Ozone Sci. Eng., 27, 447–458, 2005. </reference>
		<reference numeration="47" content_type="text"> Reeser,~D I., Jammoul, A., Clifford,~D., Brigante,~M., D&apos;Anna,~B., George,~C., and Donaldson,~A D J.: Photoenhanced reactive uptake of gas phase ozone by chlorophyll at the sea-water surface, J. Phys. Chem. C., 113, 2071-2077, 2009. </reference>
		<reference numeration="48" content_type="text"> Sakamoto,~M., Cai,~X., Hara,~M., Tojo,~S., Fujitsuka,~M., and Majima,~T.: Transient absorption spectra and lifetimes of benzophenone ketyl radicals in the excited state, J. Phys. Chem. A., 108, 8147–8150, 2004. </reference>
		<reference numeration="49" content_type="text"> Schweitzer,~F., Mirabel,~P., and George,~C.: Uptake of hydrogen halides by water droplets, J. Phys. Chem. A., 104, 72–76, 2000. </reference>
		<reference numeration="50" content_type="text"> Sempere,~R. and Kawamura,~K.: Trans-hemispheric contribution of C2-C10 a, w-dicarboxylic acids, and related polar compounds to water-soluble organic carbon in the western Pacific aerosols in relation to photochemical oxidation reactions, Global Biogeochem. Cy., 17, 38/31–38/15, 2003. </reference>
		<reference numeration="51" content_type="text"> Shizuka,~H. and Obuchi,~H.: Anion-induced triplet quenching of aromatic ketones by nanosecond laser photolysis, J. Phys. Chem., 86, 1297–1302, 1982. </reference>
		<reference numeration="52" content_type="text"> von Glasow,~R., Crutzen,~P J., Heinrich,~D H., and Karl,~K T.: Tropospheric halogen chemistry, in: Treatise on Geochemistry, Pergamon, Oxford, 1–67, 2003. </reference>
		<reference numeration="53" content_type="text"> Wu,~J J. and Masten,~S J.: Oxidation kinetics of phenolic and indolic compounds by ozone: applications to synthetic and real swine manure slurry, Water Res., 36, 1513–1526, 2002. </reference>
		<reference numeration="54" content_type="text"> Zehavi,~D. and Rabani,~J.: Oxidation of aqueous bromide ions by hydroxyl radicals. Pulse radiolytic investigation, J. Phys. Chem., 76, 312–319, 1972. </reference>
	</references>
</article>

