Laboratory studies of photochemistry and gas phase radical reaction kinetics relevant to planetary atmospheres

2012 ◽  
Vol 41 (19) ◽  
pp. 6318 ◽  
Author(s):  
M. A. Blitz ◽  
P. W. Seakins
Keyword(s):  
Reaction Kinetics ◽  
Gas Phase ◽  
Radical Reaction ◽  
Planetary Atmospheres ◽  
Laboratory Studies

Laser flash photolysis studies of radical–radical reaction kinetics: The O(3PJ)+BrO reaction

1995 ◽  
Vol 102 (10) ◽  
pp. 4131-4142 ◽  
Author(s):  
R. P. Thorn ◽  
J. M. Cronkhite ◽  
J. M. Nicovich ◽  
P. H. Wine
Keyword(s):  
Reaction Kinetics ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Radical Reaction ◽  
Laser Flash

Laser Flash Photolysis Studies of Radical−Radical Reaction Kinetics:  The HO2+ BrO Reaction

1998 ◽  
Vol 102 (33) ◽  
pp. 6651-6658 ◽  
Author(s):  
J. M. Cronkhite ◽  
R. E. Stickel ◽  
J. M. Nicovich ◽  
P. H. Wine
Keyword(s):  
Reaction Kinetics ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Radical Reaction ◽  
Laser Flash

scholarly journals Atmospheric β-Caryophyllene-Derived Ozonolysis Products at Interfaces

2018 ◽  
Author(s):  
Ariana Gray Bé ◽  
Hilary M. Chase ◽  
Liu, Yangdongliu ◽  
Mary Alice Upshur ◽  
Zhang, Yue ◽  
...  
Keyword(s):  
Gas Phase ◽  
Structural Information ◽  
High Surface ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Laboratory Studies ◽  
Sum Frequency ◽  
Sum Frequency Generation Spectroscopy ◽  
Surface Active ◽  
Cloud Activation

<p>By integrating organic synthesis, secondary organic aerosol synthesis and collection, DFT calculations, and vibrational sum frequency generation spectroscopy, we identify close spectral matches between the surface vibrational spectra of β-caryophyllene-derived secondary organic material and those of β-caryophyllene aldehyde and β-caryophyllonic acid at various interfaces. Combined with the record high surface tension depression described previously for these same oxidation products, we discuss possibilities for an intrinsically chemical origin for cloud activation by terpene-derived surfactants. Although the present study does not unequivocally identify the synthesized and analyzed oxidation products on the β-caryophyllenederived SOM surfaces, these two compounds appear to be the most surface active out of the series, and have also been foci of previous β-caryophyllene field and laboratory studies.</p><p>An orientation analysis by phase-resolved SFG spectroscopy reveals a “pincer-like” configuration of the β-caryophyllene oxidation products, albeit on a model quartz surface, that somewhat resembles the orientation of inverse double-tailed surfactants at the surfaces biological systems. The structural information suggests that the less polar moiety of a surface-localized oxidation product, such as those studied here, may be the first site-of-contact for a gas-phase molecule approaching an SOA particle containing surface-active β-caryophyllene oxidation products.</p>

scholarly journals Inorganic bromine in the marine boundary layer: a critical review

2003 ◽  
Vol 3 (3) ◽  
pp. 2963-3050 ◽  
Author(s):  
R. Sander ◽  
W. C. Keene ◽  
A. A. P. Pszenny ◽  
R. Arimoto ◽  
G. P. Ayers ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Gas Phase ◽  
Marine Boundary Layer ◽  
Sea Water ◽  
Ocean Surface ◽  
Sea Salt ◽  
Future Research ◽  
Laboratory Studies ◽  
Model Calculations ◽  
Sea Salt Aerosol

Abstract. The cycling of inorganic bromine in the marine boundary layer (mbl) has received increased attention in recent years. Bromide, a constituent of sea water, is injected into the atmosphere in association with sea-salt aerosol by breaking waves on the ocean surface. Measurements reveal that supermicrometer sea-salt aerosol is depleted in bromine by about 50% relative to conservative tracers, whereas marine submicrometer aerosol is often enriched in bromine. Model calculations, laboratory studies, and field observations strongly suggest that these depletions reflect the chemical transformation of particulate bromide to reactive inorganic gases that influence the processing of ozone and other important constituents of marine air. However, currently available techniques cannot reliably quantify many \\chem{Br}-containing compounds at ambient concentrations and, consequently, our understanding of inorganic Br cycling over the oceans and its global significance are uncertain. To provide a more coherent framework for future research, we have reviewed measurements in marine aerosol, the gas phase, and in rain. We also summarize sources and sinks, as well as model and laboratory studies of chemical transformations. The focus is on inorganic bromine over the open oceans, excluding the polar regions. The generation of sea-salt aerosol at the ocean surface is the major tropospheric source producing about 6.2 Tg/a of bromide. The transport of  Br from continents (as mineral aerosol, and as products from biomass-burning and fossil-fuel combustion) can be of local importance. Transport of degradation products of long-lived Br-containing compounds from the stratosphere and other sources contribute lesser amounts. Available evidence suggests that, following aerosol acidification, sea-salt bromide reacts to form Br2 and BrCl that volatilize to the gas phase and photolyze in daylight to produce atomic Br and Cl. Subsequent transformations can destroy tropospheric ozone, oxidize dimethylsulfide (DMS) and hydrocarbons in the gas phase and S(IV) in aerosol solutions, and thereby potentially influence climate. The diurnal cycle of gas-phase \\Br and the corresponding particulate Br deficits are correlated. Higher values of Br in the gas phase during daytime are consistent with expectations based on photochemistry. Mechanisms that explain the widely reported accumulation of particulate Br in submicrometer aerosols are not yet understood. We expect that the importance of inorganic Br cycling will vary in the future as a function of both increasing acidification of the atmosphere (through anthropogenic emissions) and climate changes. The latter affects bromine cycling via meteorological factors including global wind fields (and the associated production of sea-salt aerosol), temperature, and relative humidity.

Electronic Spectra of the Triacetylene Cation (HC6H+) and Protonated Triacetylene (HC6H2+) Tagged with Ar

2019 ◽  
Vol 72 (4) ◽  
pp. 260 ◽  
Author(s):  
Ugo Jacovella ◽  
Giel Muller ◽  
Katherine J. Catani ◽  
Nastasia I. Bartlett ◽  
Evan J. Bieske
Keyword(s):  
Electronic Spectrum ◽  
Gas Phase ◽  
Band System ◽  
Argon Atom ◽  
Planetary Atmospheres ◽  
Phase Spectrum ◽  
Tandem Mass ◽  
Interstellar Clouds ◽  
Combustion Processes ◽  
First Time

Polyacetylene cations (HC2nH+) play important roles in combustion processes and in the chemistry of planetary atmospheres and interstellar clouds. Here we report the electronic spectrum for the triacetylene cation (HC6H+) recorded over the 300–610nm range by photodissociating mass-selected ions tagged with argon atoms in a tandem mass spectrometer. The spectrum shows three band systems that are assigned to (origin transition 16665cm−1), (origin transition 23916cm−1), and (origin transition 29920cm−1). Although the band system is well known, the and band systems are observed for the first time in the gas phase. In addition, the electronic spectrum of the protonated triacteylene cation tagged with an argon atom (HC6-Ar) is reported, providing the first gas-phase spectrum for this species.

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