Nascent HF† and HSO(2A′) formations in the elementary reactions of F + H2S and HS + O3 and the internal energy distributions

1995 ◽  
Vol 73 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Yasunori Yoshimura ◽  
Toshio Kasai ◽  
Hiroshi Ohoyama ◽  
Keiji Kuwata
Keyword(s):  
Internal Energy ◽  
Rotational Temperature ◽  
Similar Data ◽  
Vibrational States ◽  
Energy Distributions ◽  
Vibrationally Excited ◽  
Elementary Reactions ◽  
Electronically Excited ◽  
Vibrational Bands ◽  
Rotational Distribution

Chemiluminescence of the vibrationally excited HF† and of the electronically excited HSO* in the 2A′ state were observed in the elementary reactions of F + H2S and HS + O3. In the F + H2S reaction, the vibrational populations of HF† in ν = 3 and 4 were found to be nonstatistical but the rotational distribution in the ν = 4 state was found to be Boltzmann-like with a rotational temperature of 700 K, confirming similar data obtained by different methods. The HSO* emission was observed in the HS + O3 elementary reaction. The spectrum of HSO* characterized by broad vibrational bands indicates nonstatistical excitation for the rotational and vibrational states. Keywords: chemiluminescence, internal energy distribution, F + H2S, HS + O3, HF†, HSO*.

scholarly journals Model of daytime emissions of electronically-vibrationally excited products of O<sub>3</sub> and O<sub>2</sub> photolysis: application to ozone retrieval

2006 ◽  
Vol 24 (11) ◽  
pp. 2823-2839 ◽  
Author(s):  
V. A. Yankovsky ◽  
R. O. Manuilova
Keyword(s):  
Atomic Oxygen ◽  
Energy Exchange ◽  
Electronic States ◽  
Vibrational States ◽  
Vibrationally Excited ◽  
Proposed Model ◽  
Vibrational Levels ◽  
Electronically Excited ◽  
Basic Facts ◽  
Kinetics Of

Abstract. The traditional kinetics of electronically excited products of O3 and O2 photolysis is supplemented with the processes of the energy transfer between electronically-vibrationally excited levels O2(a1Δg, v) and O2(b1Σ+g, v), excited atomic oxygen O(1D), and the O2 molecules in the ground electronic state O2(X3Σg−, v). In contrast to the previous models of kinetics of O2(a1Δg) and O2 (b1Σ+g), our model takes into consideration the following basic facts: first, photolysis of O3 and O2 and the processes of energy exchange between the metastable products of photolysis involve generation of oxygen molecules on highly excited vibrational levels in all considered electronic states – b1Σ+g, a1Δg and X3Σg−; second, the absorption of solar radiation not only leads to populating the electronic states on vibrational levels with vibrational quantum number v equal to 0 – O2(b1Σ+g, v=0) (at 762 nm) and O2(a1Δg, v=0) (at 1.27 µm), but also leads to populating the excited electronic–vibrational states O2(b1Σ+g, v=1) and O2(b1Σ+g, v=2) (at 689 nm and 629 nm). The proposed model allows one to calculate not only the vertical profiles of the O2(a1Δg, v=0) and O2(b1Σ

THE HYDROGEN–CHLORINE SYSTEM IN THE MM PRESSURE RANGE: I. ENERGY DISTRIBUTION AMONG VIBRATIONALLY EXCITED STATES

1964 ◽  
Vol 42 (10) ◽  
pp. 2176-2192 ◽  
Author(s):  
F. D. Findlay ◽  
J. C. Polanyi
Keyword(s):  
Excited States ◽  
Rotational Temperature ◽  
Relative Rate ◽  
Infrared Emission ◽  
Vibrational States ◽  
Vibrationally Excited ◽  
Experimental Conditions ◽  
Reduced Pressure ◽  
A Chain ◽  
First Time

When atomic plus molecular hydrogen coming from a Wood's discharge tube are mixed with molecular chlorine, infrared emission is observed (1). At low reagent pressures, ~10−2 mm Hg, this emission can be related to the relative rate of the reaction H + Cl2 → HCl†ν + Cl proceeding to form HCl in vibrationally excited states ν = 1–6, of the ground electronic state. In the present work this system has been investigated for the first time at ~100 × the reagent pressure (~1 mm Hg). The reaction was shown to proceed by a chain mechanism. The translational–rotational temperature was 1300 ± 100 °K under the experimental conditions normally used. The vibrational distribution was notable for the presence of vibrators in levels ν = 7 and 8, which are respectively 4 and 10 kcal higher in energy than the exothermicity of the H + Cl2 reaction. The population in these levels appeared to be related to that in the levels with [Formula: see text]; it was proposed that vibrational–vibrational exchange among these lower levels was responsible for populating the higher ones. A simple model yielded a collision efficiency for HCl†ν=1 + HCl†ν=6 → HCl†ν=7 + HCl†ν=0, of Z1,6t = 6 × 103 collisions per transfer. Addition of HCl to the reaction mixture brought about a redistribution among vibrationally excited states indicative of a fast vibrational transfer, HClν=0 + HCl†ν=2 → 2 HCl†ν=1.At reduced pressure of HCl† the stationary-state distribution among higher vibrational states approximated closely to that observed at 10−2 mm Hg total pressure (where collisional deactivation is insignificant), suggesting that collisional deactivation was not of major importance even at the pressure used in the present work. In order to account for the high translational–rotational temperature, in the absence of substantial vibrational deactivation, it was necessary to suppose that the greater part of the energy liberated by the reaction H + Cl2 went directly into translational and rotational motion of the products.

scholarly journals Study of the Vibrational Predissociation of the NeBr2 Complex by Computational Simulation Using the Trajectory Surface Hopping Method

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 2029
Author(s):  
Ernesto García-Alfonso ◽  
Maykel Márquez-Mijares ◽  
Jesús Rubayo-Soneira ◽  
Nadine Halberstadt ◽  
Kenneth C. Janda ◽  
...  
Keyword(s):  
Energy Surface ◽  
Computational Simulation ◽  
Kinetic Mechanism ◽  
Experimental Methods ◽  
Classical Dynamics ◽  
Vibrational States ◽  
Surface Hopping ◽  
Vibrational Predissociation ◽  
New Information ◽  
Rotational Distribution

The vibrational predissociation of NeBr2 has been studied using a variety of theoretical and experimental methods, producing a large number of results. It is therefore a useful system for comparing different theoretical methods. Here, we apply the trajectory surface hopping (TSH) method that consists of propagating the dynamics of the system on a potential energy surface (PES) corresponding to quantum molecular vibrational states with possibility of hopping towards other surfaces until the van der Waals bond dissociates. This allows quantum vibrational effects to be added to a classical dynamics approach. We have also incorporated the kinetic mechanism for a better compression of the evolution of the complex. The novelty of this work is that it allows us to incorporate all the surfaces for (v=16,17,…,29) into the dynamics of the system. The calculated lifetimes are similar to those previously reported experimentally and theoretically. The rotational distribution, the rotational energy and jmax are in agreement with other works, providing new information for this complex.

scholarly journals Evidence of a significant rotational non-LTE effect in the CO<sub>2</sub> 4.3 µm PFS-MEX limb spectra

2017 ◽  
Vol 10 (1) ◽  
pp. 265-271 ◽  
Author(s):  
Alexander A. Kutepov ◽  
Ladislav Rezac ◽  
Artem G. Feofilov
Keyword(s):  
Near Infrared ◽  
Thermal Structure ◽  
Radiative Lifetime ◽  
Martian Atmosphere ◽  
Vibrational States ◽  
Rotational States ◽  
First Results ◽  
Rotational Distribution ◽  
Multi Level ◽  
Excited Molecules

Abstract. Since January 2004, the planetary Fourier spectrometer (PFS) on board the Mars Express satellite has been recording near-infrared limb spectra of high quality up to the tangent altitudes ≈ 150 km, with potential information on density and thermal structure of the upper Martian atmosphere. We present first results of our modeling of the PFS short wavelength channel (SWC) daytime limb spectra for the altitude region above 90 km. We applied a ro-vibrational non-LTE model based on the stellar astrophysics technique of accelerated lambda iteration (ALI) to solve the multi-species and multi-level CO2 problem in the Martian atmosphere. We show that the long-standing discrepancy between observed and calculated spectra in the cores and wings of 4.3 µm region is explained by the non-thermal rotational distribution of molecules in the upper vibrational states 10011 and 10012 of the CO2 main isotope second hot (SH) bands above 90 km altitude. The redistribution of SH band intensities from band branch cores into their wings is caused (a) by intensive production of the CO2 molecules in rotational states with j > 30 due to the absorption of solar radiation in optically thin wings of 2.7 µm bands and (b) by a short radiative lifetime of excited molecules, which is insufficient at altitudes above 90 km for collisions to maintain rotation of excited molecules thermalized. Implications for developing operational algorithms for massive processing of PFS and other instrument limb observations are discussed.

Internal energy distributions from nitrogen dioxide fluorescence. 1. Cumulative sum method

1993 ◽  
Vol 97 (39) ◽  
pp. 9890-9903 ◽  
Author(s):  
H. S. Johnston ◽  
C. E. Miller ◽  
B. Y. Oh ◽  
K. O. Patten ◽  
W. N. Sisk
Keyword(s):  
Nitrogen Dioxide ◽  
Internal Energy ◽  
Cumulative Sum ◽  
Energy Distributions ◽  
Cumulative Sum Method
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