Photochemistry of HNO/sub 3/ and ClNO/sub 3/
The techniques of laser flash photolysis/resonance fluorescence (FP/RF) and flash photolysis/laser absorption (FP/LA) were used to study the reactions, (2) HO + HNO/sub 3/ ..-->.. H/sub 2/O + NO/sub 3/, (4) HO + H/sub 2/O/sub 2/ ..-->.. H/sub 2/O + HO/sub 2/, (10) Cl + HNO/sub 3/ ..-->.. products, (11) ClONO/sub 2/ + H..nu.. ..-->.. products. The results for reaction (2) are k/sub 2/ = (1.52 +- 0.43) x 10/sup -14/ exp (644 +- 79/T) cm/sup 3/ molecule/sup -1/s/sup -1/ from 218 to 363K, independent of pressure from 10 to 50 Torr Ar in the FP/RF experiments; phi/sub prod/ (NO/sub 3/ at low fluence) = 1.05 +- 0.26 with k/sub 2/ and phi/sub prod/ (NO/sub 3/) found to be pressure, concentration and fluence dependent, having a strong self-correlation in the 298K FP/LA experiments. Rate constants for reactions (4) and (10) were measured to be k/sub 4/ = (1.81 +- 0.24) x 10/sup -12/ cm/sup 3/ molecule/sup -1/s/sup -1/ and k/sub 10/ = (6.5 +- 3.4) x 10/sup -15/ cm/sup 3/ molecule/sup -1/s/sup -1/ at 298K and 10 Torr Ar; however, for (10) phi/sub prod/ (NO/sub 3/) less than or equal to 0.05. The FP/LA study of (11) found phi/sub prod/ (NO/sub 3/) = 0.55/sub -0.1//sup +0/ /sup 3/ at pressures from 20 to 100 Torr of Ar or CH/sub 4/, showing the major photodissociation channel to yield Cl and NO/sub 3/. The peak absorption cross section for the NO/sub 3/ (0,0) band was determined to be 1.9 x 10/sup -17/ cm/sup 2/ molecule/sup -1/ at 661.9 nm. The high resolution lineshape measured in this study was scaled to match integrated absorption coefficients determined in more direct but lower resolution studies. Under very high resolution (< or = 200 MHz) the band was structureless and would not fluoresce despite a lack of photodissociation. It was found to fit well to two overlapping Lorentzians in agreement with some theories of intramolecular energy transfer.
- Research Organization:
- Lawrence Berkeley Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5611280
- Report Number(s):
- LBL-13473; ON: DE82005627
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
CHLORINE
PHOTOLYSIS
CHLORINE OXIDES
HYDROGEN PEROXIDE
HYDROXYL RADICALS
CHEMICAL REACTIONS
NITRIC ACID
NITROGEN OXIDES
ABSORPTION SPECTROSCOPY
CHEMICAL REACTION KINETICS
DYE LASERS
FLUORESCENCE SPECTROSCOPY
LASER SPECTROSCOPY
CHALCOGENIDES
CHLORINE COMPOUNDS
DECOMPOSITION
ELEMENTS
EMISSION SPECTROSCOPY
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
LASERS
LIQUID LASERS
NITROGEN COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PEROXIDES
PHOTOCHEMICAL REACTIONS
RADICALS
REACTION KINETICS
SPECTROSCOPY
400500* - Photochemistry
400600 - Radiation Chemistry