Mass Spectrometric Contributions to Problems Related to the Chemistry of Atmospheres

Abstract

Recent mass spectrometric studies of species and processes relevant to the chemistry of atmospheres are reported. New species have been detected, including HO(3); a stratospheric reservoir of OH radicals; the [H(2)O(+)O(2)(-)] charge transfer complex, central to the atmospheric photonucleation theory; and the OSOSO oxide and its cation, likely present in the Io's atmosphere. As to ionic processes, a new route to tropospheric N(2)O in air ionized by lightning and coronas is reported, as well as the complex chemistry promoted by ionization of ozone/freon and ozone/carbonyl sulfide mixtures and the formation of O(5)(+), relevant to the problem of (18)O excess in stratospheric ozone.

Ions in space

“…Consequently, when raw sunlight encounters an atmosphere, it produces ions. Earth's oxygen-rich, nitrogen-dominated atmosphere is atypical of Solar System planetary atmospheres, but the general features of chemistry in the Earth's ionosphere (Ferguson, 1975;Reid, 1976;Ferguson, Fehsenfeld, & Albritton, 1979;Smith & Adams, 1980;Ferguson & Arnold, 1981;Mitra, 1981;Viggiano, 1993;Smith & Spanel, 1995;Squires, 1997;MacTaylor & Castleman, 2000;de Petris, 2002) are applicable to most planets (Mahajan & Kar, 1988;Nagy, Cravens, & Waite, 1995;Kar, 1996;Waite et al, 1997;Nagy & Cravens, 1998;Shinagawa, 2000Shinagawa, , 2004Majeed et al, 2004). At the highest altitudes, atmospheric gas molecules encounter photolyzing as well as photoionizing radiation, and so the predominant ions are atomic cations (O þ in the atmospheres of Earth, Venus, and Mars, H þ in the outer solar system environments).…”

Atmospherically relevant ion chemistry of ozone and its cation

“…Other experiments, performed on a ZABSpec oa-TOF multi-sector mass spectrometer equipped with a high-pressure source (0.01-0.3 Torr), have allowed the detection of the adducts [XO 3 ] þ that have been mass-selected and structurally analyzed by MIKE and CAD mass spectrometry. The reactivity pattern generally identified (de Petris, 2002) is the following:…”

Trifluoroacetic Acid and Trifluoroacetic Anhydride Radical Cations Dissociate near the Ionization Limit

“…Plasma-assisted combustion processes are of great importance in advanced propulsion systems, − while gas-phase ions play a central role in interstellar chemistry. − In the atmosphere, the primary cations N 2 + , O 2 + , and NO + eventually react with H 2 O to form hydrates [H 3 O­(H 2 O) n ] + by charge transfer . Numerous studies indicate that these cations react quickly with organic molecules in further electron transfer reactions producing cationic species. − …”

“…Information about the stability of cationic species that could be formed from the reactions of fluorinated compounds is scarce. Some years ago, de Petris et al , studied the cationic species formed by reactions of O 3 with hydrogenated halocarbons in ionized mixtures, observing the formation of CHXYO 3 + (X = H, Cl, F; Y = Cl, F), which are metastable and lose CO. More recently, Oomens and Morton revisited the reactions of CF 3 + with aldehydes and ketones using infrared multiple photon dissociation to investigate the adducts and branching ratios of further decomposition . Perfluorinated free radicals, such as CF 3 O n and FCO n ( n = 1 and 2), are known to be involved in the formation of tropospheric pollutants under environmental conditions .…”