Optical selection in double-resonant two-photon photodissociation: near-threshold state-to-state fragmentation dynamics of NO/sub 2/ + 2h nu. -->. NO(X /sup 2/PI/sub 1/2/, v = 0, J,. lambda. ) + O(/sup 1/D)
Optical-optical double resonance is employed to achieve state-to-state resolution in two-photon photodissociation. NO/sub 2/ seeded in a free-jet expansion is dissociated by sequential two-photon absorption in the region of 488 nm, just above the threshold for production of O(/sup 1/D). The channel to produce excited oxygen is observed to dominate the formation of vibrationally cold NO(X /sup 2/PI, nu = 0), which is detected by resonant two-photon ionization. For two-photon photolysis energies within 100 cm/sup 1 -/ of threshold, photodissociation dynamics, manifested in NO rotational and ..lambda..-doublet state distributions, are observed to be a sensitive function of parent intermediate state. NO populations are an oscillatory function of J, with varying patterns of ..lambda..-doublet preference that change with selected NO/sub 2/ intermediate state. Certain features in the photodissociation spectrum of NO/sub 2/ in this region are seen to correlate with product NO state total parity. At energies higher above threshold (> 200 cm/sup -1/), the oscillatory behavior in J is less pronounced and, accordingly, less sensitive to total photolysis energy. In this region a uniform ..lambda..-doublet preference also emerges.
- Research Organization:
- Cornell Univ., Ithaca, NY
- OSTI ID:
- 5895617
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 89:26
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
NITRIC OXIDE
ELECTRONIC STRUCTURE
ROTATIONAL STATES
NITROGEN DIOXIDE
DISSOCIATION
RESONANCE ABSORPTION
CHEMICAL LASERS
EXPERIMENTAL DATA
MULTI-PHOTON PROCESSES
PARITY
PHOTOLYSIS
QUANTUM MECHANICS
ABSORPTION
CHALCOGENIDES
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ENERGY LEVELS
EXCITED STATES
INFORMATION
LASERS
MECHANICS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PARTICLE PROPERTIES
PHOTOCHEMICAL REACTIONS
400500* - Photochemistry
500200 - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)