Spin–orbit relaxation kinetics of Br(4 2<i>P</i>1/2)

Johnson, Ray O.; Perram, Glen P.; Roh, Won B.

doi:10.1063/1.471422

Cited by 15 publications

(7 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, as was noted in Ref. 74, its value is just at the limit of experimental accuracy determined mainly by the purity of the rare gas. As such, it should be taken only as an upper bound for the actual quenching rate.…”

Section: Hebr Collision and Transport Propertiesmentioning

confidence: 81%

Complete basis set extrapolation limit for electronic structure calculations: Energetic and nonenergetic properties of HeBr and HeBr2 van der Waals dimers

Lara‐Castells

Krems

Buchachenko

et al. 2001

The Journal of Chemical Physics

View full text Add to dashboard Cite

The lowest 2 ⌺ ϩ and 2 ⌸ electronic states of the HeBr molecule have been calculated by the ab initio coupled cluster approach in conjunction with a series of increasing size augmented correlation-consistent basis sets of double through quintuple zeta quality. Different extrapolation formulas to the complete basis set limit have been tested by comparing estimated and actual quintuple zeta quality counterpoise corrected interaction energies. Frozen-core approach is checked by performing calculations in which all electrons are correlated. The potential energy surfaces of the HeBr 2 van der Waals complex have been obtained from the HeBr potentials by means of the diatomic-in-molecule approach. Finally, transport, scattering, and spectroscopic properties of HeBr and HeBr 2 (B) systems derived from ab initio data for different basis sets are examined. It is shown that their convergence closely follows the convergence of corresponding potential energy surfaces.

show abstract

Section: Hebr Collision and Transport Propertiesmentioning

confidence: 81%

Complete basis set extrapolation limit for electronic structure calculations: Energetic and nonenergetic properties of HeBr and HeBr2 van der Waals dimers

Lara‐Castells

Krems

Buchachenko

et al. 2001

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…Br( 2 P 1/2 ) atoms are rapidly relaxed to Br( 2 P 3/2 ) by collision with N 2 . 34 The initial Br atom concentration was determined by titration with excess O 3 ((4-8) × 10 18 molecule cm -3 ) and measurement of the resulting BrO concentration. 29 Br( 2 P 3/2 ) atoms react with DMS to give the Br-DMS adduct which has a broad absorption band in the region from 300 to 450 nm.…”

Section: Methodsmentioning

confidence: 99%

“…In the study of the Br + DMS reaction, Br atoms were generated by the 355 nm photolysis of Br 2 ((8−20) × 10 13 molecule cm -3 ). Br( 2 P 1/2 ) atoms are rapidly relaxed to Br( 2 P 3/2 ) by collision with N 2 . The initial Br atom concentration was determined by titration with excess O 3 ((4−8) × 10 18 molecule cm -3 ) and measurement of the resulting BrO concentration …”

Section: Methodsmentioning

confidence: 99%

Cavity Ring-Down Spectroscopic Study of the Reactions of Br Atoms and BrO Radicals with Dimethyl sulfide

et al. 2001

View full text Add to dashboard Cite

The title reactions were studied using cavity ring-down spectroscopy in 100 Torr of N2 diluent at 278−333 K. The equilibrium constant and rates of the forward and reverse reactions of the Br + DMS ⇄ Br−DMS equilibrium were determined to be K = (4.1 ± 0.3) × 10-15 cm3 molecule-1, k forward = (5.0 ± 0.2) × 10-11 cm3 molecule-1 s-1, and k backward = (1.2 ± 0.2) × 104 s-1 at 300 K in 100 Torr of N2. The absorption cross section of the Br−DMS adduct at 338.3 nm was σ = (1.2 ± 0.2) × 10-17 cm2 molecule-1. An upper limit of k < 1 × 10-18 cm3 molecule-1 s-1 was established for the reaction of O2 with the Br−DMS adduct. The kinetics of the reaction of BrO with DMS were well described by the Arrhenius expression k = (1.3 ± 0.1) × 10-14 exp[(1033 ± 265)/T] cm3 molecule-1 s-1 (k = 4.2 × 10-13 cm3 molecule-1 s-1 at 298 K). The uncertainties are 2 standard deviations from regression analyses.

show abstract

“…For the conditions used in the quantum yield experiments, the two spin states of the bromine atoms ( 2 P 3/2 and 2 P 1/2 ) should have reached their equilibrium ratio within a millisecond. To be sure that this was not a problem, some runs used a mixture of 5% H 2 in N 2 as the carrier gas to increase the relaxation rate by a factor of ten [ Johnson et al , 1996]; there were no detectable differences in the yields or time dependence of Br signals when H 2 was present. The bromine atom signals increased linearly with pulse energy up to well above 1 mJ per pulse; quantum yield measurements were made with pulse energies of 0.8 to 1.2 mJ per pulse.…”

Section: Description Of Experimentsmentioning

confidence: 99%

Measurements of quantum yields of bromine atoms in the photolysis of bromoform from 266 to 324 nm

et al. 2003

View full text Add to dashboard Cite

1] The quantum yield for the formation of bromine atoms in the photolysis of bromoform, CHBr 3 , has been measured between 266 and 324 nm. For 303 to 306 nm the quantum yields are unity within the experimental uncertainty of the measurements. At longer wavelengths, where the bromoform cross sections decrease rapidly, an apparent trend to slightly lower quantum yields is probably the result of systematic and random errors or incorrect CHBr 3 absorption cross sections. Support for a unit quantum yield for all wavelengths longer than 300 nm comes from the recent theoretical calculations of Peterson and Francisco. At 266 nm the bromine atom quantum yield is 0.76 (±0.03), indicating that at least one additional dissociation channel becomes important at shorter wavelengths. For modeling of the troposphere, it is recommended that a quantum yield of unity be used for wavelengths of 300 nm and longer. Measurements of quantum yields of bromine atoms in the photolysis of bromoform from 266 to 324 nm,

show abstract

Spin–orbit relaxation kinetics of Br(4 2P1/2)

Cited by 15 publications

References 34 publications

Complete basis set extrapolation limit for electronic structure calculations: Energetic and nonenergetic properties of HeBr and HeBr2 van der Waals dimers

Complete basis set extrapolation limit for electronic structure calculations: Energetic and nonenergetic properties of HeBr and HeBr2 van der Waals dimers

Cavity Ring-Down Spectroscopic Study of the Reactions of Br Atoms and BrO Radicals with Dimethyl sulfide

Measurements of quantum yields of bromine atoms in the photolysis of bromoform from 266 to 324 nm

Contact Info

Product

Resources

About