Ab initio study of the chlorine nitrate protonation reaction: Implications for loss of ClONO[sub 2] in the stratosphere

Journal Article · Thu Jun 24 00:00:00 EDT 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100127a012· OSTI ID:6019267

Lee, T J ^[1]; Rice, J E ^[2]

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1. NASA Ames Research Center, Moffett Field, CA (United States)
2. IBM Research Division, San Jose, CA (United States)

The energetics of the protonation reaction of chlorine nitrate, ClONO[sub 2], have been investigated using state-of-the art ab initio quantum mechanical methods. Specifically, equilibrium structures, vibrational spectra, and thermochemical data have been obtained using second-order Moeller-Plesset perturbation theory (MP2), singles and doubles coupled-cluster theory (CCSD), and the CCSD(T) method, which includes a preturbational estimate of the effects of connected triple excitations. It is shown that the lowest energy form of protonated ClONO[sub 2] corresponds to a complex between HOCl and NO[sub 2][sup +] -- similar to the situation for HONO[sub 2] and CH[sub 3]ONO[sub 2]. The proton affinity of ClONO[sub 2] is determined to be 176.8 [+-] 3 kcal/mol (0 K) while the second most stable isomer of protonated ClONO[sub 2] is 20 kcal/mol higher in energy. The HOCl [hor ellipsis]NO[sub 2][sup +] complex is bound by 12.9 [+-] 2 kcal/mol. The heat of formation of ClONO[sub 2] is computed to be 7.4 kcal/mol at 298 K, in good agreement with the experimental value of 6.3 kcal/mol. The present study supports a recent hypothesis that the reaction of ClONO[sub 2] on the surface of polar stratospheric clouds (PSCs) is proton catalyzed, although the specific mechanism is different. The results are also consistent with other recent findings concerning the reactions of ClONO[sub 2] and HOCl with HCl on the surface of PSCs. 59 refs., 1 fig., 10 tabs.

• OSTI ID: 6019267
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 97:25; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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54 ENVIRONMENTAL SCIENCES
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Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
99 GENERAL AND MISCELLANEOUS
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ATMOSPHERIC CHEMISTRY
BARYONS
CATALYSIS
CHEMICAL REACTIONS
CHEMISTRY
CHLORINE COMPOUNDS
CHLORINE NITRATES
CLOUDS
COMPUTERIZED SIMULATION
DATA
EARTH ATMOSPHERE
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HALOGEN COMPOUNDS
INFORMATION
ISOMERS
LAYERS
MECHANICS
NITRATES
NITROGEN COMPOUNDS
NUCLEONS
NUMERICAL DATA
OXYGEN COMPOUNDS
OZONE LAYER
PROTONS
QUANTUM MECHANICS
SIMULATION
STRATOSPHERE
THEORETICAL DATA
THERMODYNAMICS