Falloff curve and specific rate constants for the reaction NO/sub 2/ + NO/sub 2/ /r reversible/ N/sub 2/O/sub 4/
The rate of association of NO/sub 2/ to N/sub 2/O/sub 4/ was measured in N/sub 2/ at pressures from 1 to 207 bar. This way the reaction was observed in a large section of its falloff range. The relaxation of NO/sub 2//N/sub 2/O/sub 4/ mixtures was followed after laser flash photolysis of N/sub 2/O/sub 4/ at 248 nm. From the results the falloff curve was constructed, which gives the high- and low-pressure rate constants at 298 K (in cm/sup 3/ molecule/sup /minus/1/ s/sup /minus/1/): k/sub ass//sup infinity/ = (8.3 /plus minus/ 1.0) /times/ 10/sup /minus/13/ and k/sub ass//sup 0/ = (1.4 /plus minus/ 0.2) /times/ 10/sup /minus/33/(N/sub 2/). Earlier measurements believed to be in the low-pressure regime, have not been free from falloff effects. The low value of k/sup infinity/ was analyzed with the statistic adiabatic channel model, and specific rate constants, k(E,J), were calculated. They increase very steeply with energy just above the reaction threshold and go through maxima at low excess energies. These unusual effects are analyzed theoretically and the strong contributions are pointed out of the low-frequency vibrations which disappear during the dissociation of N/sub 2/O/sub 4/.
- Research Organization:
- Universitaet Goettingen (Germany, F.R.)
- OSTI ID:
- 6254718
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 92:15
- Country of Publication:
- United States
- Language:
- English
Similar Records
Kinetic study of the reaction CCl sub 3 + O sub 2 + M yields CCl sub 3 O sub 2 + M from 1 to 760 Torr and from 233 to 333 K
Kinetic and theoretical studies of the reactions CH sub 3 C(O)O sub 2 + NO sub 2 + M r reversible CH sub 3 C(O)O sub 2 NO sub 2 + M between 248 and 393 K and between 30 and 760 Torr
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
NITROGEN DIOXIDE
CHEMICAL REACTIONS
ABSORPTIVITY
CHEMICAL REACTION KINETICS
EXPERIMENTAL DATA
GASES
LASERS
PHOTOLYSIS
PRESSURE DEPENDENCE
TIME DEPENDENCE
CHALCOGENIDES
DATA
DECOMPOSITION
FLUIDS
INFORMATION
KINETICS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUMERICAL DATA
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYSICAL PROPERTIES
REACTION KINETICS
400201* - Chemical & Physicochemical Properties
500100 - Environment
Atmospheric- Basic Studies- (-1989)
400500 - Photochemistry