Collisional quenching and energy transfer in NS B /sup 2/Pi

Journal Article · Mon Jun 15 04:00:00 EDT 1987 · J. Chem. Phys.; (United States)

OSTI ID:6783349

Jeffries, J B; Crosley, D R

Total collisional removal rate constants k/sub d/ for the B /sup 2/Pi excited electronic state of the NS free radical are measured for several collider molecules. For the lowest vibrational level (v' = 0), k/sub d/ is the electronic quenching rate constant; and for the vibrationally excited v' = 1 and v' = 6 levels, k/sub d/ is the sum of those for electronic quenching and vibrational relaxation. Nitrogen sulfide free radicals are produced in a discharge flow reactor and the B /sup 2/Pi state is prepared and monitored by laser-induced fluorescence. Measurements are made for nine different collision partners: He, N/sub 2/, O/sub 2/, SF/sub 6/, N/sub 2/O, H/sub 2/, CH/sub 4/, CO/sub 2/, and NH/sub 3/. Except for NH/sub 3/, the thermally averaged quenching cross sections at room temperature are less than 10 A/sup 2/; this is a small value for electronic quenching of open shell diatomic radicals. For v' = 6, k/sub d/ is smaller than for v' = 1 for N/sub 2/, SF/sub 6/, N/sub 2/O, and CO/sub 2/, but larger for H/sub 2/, O/sub 2/, and He. The vibrational relaxation pathway from v' = 1 to v' = 0 constitutes about 25% of the total v' = 1 collisional removal for O/sub 2/, N/sub 2/O, and SF/sub 6/.

• Research Organization: Molecular Physics Department, SRI International, Menlo Park, California 94025
• OSTI ID: 6783349
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 86:12; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKANES
AMMONIA
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
COLLISIONS
DE-EXCITATION
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
FLUIDS
FLUORIDES
FLUORINE COMPOUNDS
GASES
HALIDES
HALOGEN COMPOUNDS
HELIUM
HYDRIDES
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
METHANE
MOLECULE COLLISIONS
MOLECULE-MOLECULE COLLISIONS
NITRIDES
NITROGEN
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PNICTIDES
QUENCHING
RADICALS
RARE GASES
SULFUR COMPOUNDS
SULFUR FLUORIDES
SULFUR NITRIDES