THE STUDY OF VIBRATIONALLY EXCITED N2 MOLECULES WITH THE AID OF AN ISOTHERMAL CALORIMETER

1963 ◽  
Vol 41 (4) ◽  
pp. 903-912 ◽  
Author(s):  
J. E. Morgan ◽  
H. I. Schiff
Keyword(s):  
Microwave Discharge ◽  
Reaction Vessel ◽  
Kcal Mole ◽  
Collision Efficiency ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
First Case ◽  
Nitrogen Stream ◽  
Excited Nitrogen ◽  
Isothermal Calorimeter

Vibrationally excited nitrogen molecules produced both by a microwave discharge in nitrogen and also by the reaction[Formula: see text]have been examined using an isothermal calorimetric probe.In the first case the energy associated with an 'active' nitrogen stream, due to vibrationally excited N2, was found to be 6.03 kcal mole−1 of total nitrogen. The subsequent relaxation of this species was found to occur almost entirely on the walls of the reaction vessel, with a collision efficiency of 4.5 × 10−4. The addition of other gases greatly accelerated the homogeneous relaxation rate. Collisional efficiencies of N2O, CO2, and Ar were found to be 0.8 × l0−4, 2.3 × 10−5, and 1.0 × 10−6 respectively.The vibrationally excited nitrogen produced by the N/NO reaction was found to possess 20 ± 4 kcal mole−1 of energy compared with the maximum of 75 kcal mole−1 allowed by the exothermicity of the reaction.

THE REACTIVE SPECIES IN ACTIVE NITROGEN

1962 ◽  
Vol 40 (6) ◽  
pp. 1082-1097 ◽  
Author(s):  
A. N. Wright ◽  
R. L. Nelson ◽  
C. A. Winkler
Keyword(s):  
Molecular Nitrogen ◽  
Reaction Vessel ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Vibrational Levels ◽  
Long Lifetime ◽  
Excited Nitrogen ◽  
A Minor ◽  
Hydrocarbon Reactions ◽  
Decomposition Of No

A study has been made of the discrepancy between the N-atom content of active nitrogen as inferred from the maximum HCN production from the reaction of many hydrocarbons, and that indicated by the extent of NO destruction. The HCN production from several hydrocarbons was similar at high reaction temperatures in a spherical reaction vessel, and was independent of reaction temperature in a cylindrical reaction vessel. The ratio (NO destroyed)/(HCN produced) was found to be independent of the mode of excitation òf the molecular nitrogen and of the N-atom concentration, and to be unaffected by the addition, upstream, of N2O or CO2. Although NH3 was found to be a minor product of the hydrocarbon reactions, HCN accounted for at least 96% of the N-atom content of the products under conditions where its formation is considered a measure of the N-atom concentration. The NO "titration" value, the maximum extent of HCN production from C2H4, and the destruction of NH3 after different times of decay of active nitrogen gave evidence that part of the NO reaction occurred, as does the NH3 reaction, with excited nitrogen molecules. The long lifetime of the N2* species capable of reaction with NO or NH3, as calculated from the above data, strongly favors its identification as low vibrational levels of the N2(A3∑u+) molecule. A consideration of the values for the NO/HCN, NH3/HCN, and NH3/NO ratios, after different times of decay, for poisoned and unpoisoned systems, suggested that the N2* responsible for the NH3 reaction is formed only during homogeneous recombination of N atoms, while the N2* responsible for reaction with NO might be produced by wall recombination as well. Possible reactions of excited molecules present in the active nitrogen – NO system that might lead to decomposition of NO without consumption of N atoms are discussed.

Spectroscopic study of the reaction of active nitrogen with some organometallic compounds

1967 ◽  
Vol 45 (16) ◽  
pp. 1891-1896 ◽  
Author(s):  
R. E. March ◽  
H. I. Schiff
Keyword(s):  
Energy Transfer ◽  
Spectroscopic Study ◽  
Organometallic Compounds ◽  
Initial Energy ◽  
Emission Lines ◽  
Kcal Mole ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
Metal Atoms

Transfer of energy from constituents in active nitrogen to gaseous organometallic compounds leads to dissociation of the organometallic and excitation of CN and (or) metal atom. Organometallic compounds of aluminium, zinc, and boron were used in this investigation. The observed emission lines from metal atoms and highly vibrationally excited CN correspond to an initial energy transfer in excess of 200 kcal/mole. The possible role of N2(5Σg+) molecules as excitors is discussed in the light of the results obtained.

EFFECT OF ADDED AMMONIA ON THE REACTIONS OF ACTIVE NITROGEN WITH CH4, C2H6, AND C2H4

1962 ◽  
Vol 40 (7) ◽  
pp. 1291-1295 ◽  
Author(s):  
A. N. Wright ◽  
C. A. Winkler
Keyword(s):  
Nitrogen Molecule ◽  
Reaction Vessel ◽  
Active Nitrogen ◽  
Flame Emission ◽  
Excited Nitrogen

The small HCN yield from the CH4 and C2H6 reactions in an unheated, cylindrical reaction vessel is greatly reduced in the presence of added NH3. The addition of NH3 completely quenches the flame emission from the CH4 reaction, and greatly reduces that from the C2H6 and C2H4 reactions. Both flame emission and HCN production from the CH4 and C2H6 reactions appear to be initiated, at reaction temperatures of about 83 °C, by an excited nitrogen molecule similar to that responsible for NH3 decomposition.

Vacuum ultraviolet chemiluminescence from the reactions of active nitrogen with I2, IBr, ICI, and ICN

1968 ◽  
Vol 46 (8) ◽  
pp. 1429-1434 ◽  
Author(s):  
L. F. Phillips
Keyword(s):  
Energy Transfer ◽  
Emission Intensity ◽  
Vacuum Ultraviolet ◽  
Nitrogen Molecule ◽  
Emission Lines ◽  
Kcal Mole ◽  
Active Nitrogen ◽  
Excitation Mechanisms ◽  
Excited Nitrogen ◽  
Cl Atoms

Numerous emission lines from excited I, Br, and Cl atoms have been observed between 1261 and 2062 Å. For the flames with I2, IBr, and ICl it is possible to assign excitation mechanisms on the basis of the dependence of emission intensity on either [N] or [N]2. In the case of dependence on [N] the emission is the result of energy transfer from an excited nitrogen molecule, which is produced by reaction of N with NI, has an energy of 185 ± 3.5 kcal/mole, and is identified with the predicted 3Δu species. The dissociation energy of NI is found to lie between 35.6 and 40 + 3.5 kcal/mole. It is proposed that excited nitrogen molecules can be produced as well as removed very rapidly by processes of the type[Formula: see text]

Mechanism of a CO–N2 laser. I. Study of the vibrational populations

1970 ◽  
Vol 48 (17) ◽  
pp. 1949-1955 ◽  
Author(s):  
F. Legay ◽  
N. Legay-Sommaire ◽  
G. Taïeb
Keyword(s):  
Infrared Spectroscopy ◽  
Population Inversion ◽  
Laser Level ◽  
Laser Line ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
Operational Characteristics ◽  
Gain Measurement ◽  
Vibrational Levels ◽  
Excited Nitrogen

A laser operating on the vibrational–rotational levels of CO populated by active nitrogen has been built and studied by infrared spectroscopy. The operational characteristics and the importance of the nature of the walls and their condition are discussed. The population of each vibrational laser level has been deduced from the gain measurement of each laser line. The mechanism of the population inversion is described in terms of the theory proposed by Treanor, Rich, and Rehm, assuming that the population of CO vibrational levels is ensured by a vibration–vibration transfer from vibrationally excited nitrogen molecules.

The Dielectric Discharge as an Efficient Generator of Active Nitrogen for Chemiluminescence and Analysis

1983 ◽  
Vol 37 (6) ◽  
pp. 545-552 ◽  
Author(s):  
John Kishman ◽  
Eric Barish ◽  
Ralph Allen
Keyword(s):  
Gas Phase ◽  
Ground State ◽  
Band System ◽  
Electrothermal Atomization ◽  
Characteristic Radiation ◽  
Gaseous Species ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
Excited Species ◽  
Intense Emission

A predominantly blue “active nitrogen” afterglow was generated in pure flowing nitrogen or in air by using a dielectric discharge at pressures from 1 to 20 Torr. The afterglow contains triplet state molecules and vibrationally excited ground state molecules. These species are produced directly by electron impact without the formation and recombination of nitrogen atoms. The most intense emission is the N2 second positive band system. The N2 first positive and N2+ first negative systems are also observed. The spectral and electrical properties of this discharge are discussed in order to establish guidelines for the analytical use of the afterglow for chemiluminescence reactions. The metastatic nitrogen efficiently transfers its energy to atomic and molecular species which are introduced into the gas phase and these excited species emit characteristic radiation. The effects of electrothermal atomization of Zn and the introduction of gaseous species (e.g., NO) on the afterglow are described.

Some chemical reactions of sulfur hexafluoride with silicon containing species stimulated by cw CO2 laser radiation

1979 ◽  
Vol 44 (7) ◽  
pp. 2092-2095 ◽  
Author(s):  
Josef Pola ◽  
Pavel Engst ◽  
Milan Horák
Keyword(s):  
Laser Radiation ◽  
Chemical Reactions ◽  
Carbon Disulfide ◽  
Sulfur Hexafluoride ◽  
Initial Pressure ◽  
Reaction Vessel ◽  
Silicon Tetrachloride ◽  
Vibrationally Excited ◽  
Cw Co2 Laser ◽  
Co2 Laser Radiation

The CO2 cw laser induced interaction of sulfur hexafluoride with chlorine, silicon tetrachloride, trichlorosilane, and methyltrichlorosilane in a glass reaction vessel has been investigated. The reaction of SF6 with glass surface yielding silicon tetrafluoride and thionyl fluoride was observed. It is inhibited by the products and its rate increases with growing initial pressure (0.6-5.3 kPa) of SF6. Presumed vibrationally excited or dissociated SF6 undergoes the same reaction in the presence of chlorine and silicon tetrachloride, too. The reaction is suppressed by the addition of trichlorosilane and methyltrichlorosilane; in these cases SiF4, SiCl4 and HCl, or SiF4, SiCl4, HCl, acetylene and carbon disulfide are formed. The products indicate a non-sensitizing action of SF6 and a specific reaction channel for the formation of CS2 not attainable by pyrolysis.

scholarly journals The role of vibrationally excited oxygen and nitrogen in the ionosphere during the undisturbed and geomagnetic storm period of 6-12 April 1990

1998 ◽  
Vol 16 (5) ◽  
pp. 589-601 ◽  
Author(s):  
A. V. Pavlov
Keyword(s):  
Loss Rate ◽  
Boltzmann Distribution ◽  
Rate Coefficients ◽  
Ion Chemistry ◽  
Vibrationally Excited ◽  
Model Calculations ◽  
F Region ◽  
Neutral Temperature ◽  
The Difference ◽  
Excited Nitrogen

Abstract. We present a comparison of the observed behavior of the F-region ionosphere over Millstone Hill during the geomagnetically quiet and storm periods of 6–12 April 1990 with numerical model calculations from the IZMIRAN time-dependent mathematical model of the Earth's ionosphere and plasmasphere. The major enhancement to the IZMIRAN model developed in this study is the use of a new loss rate of O+(4S) ions as a result of new high-temperature flowing afterglow measurements of the rate coefficients K1 and K2 for the reactions of O+(4S) with N2 and O2. The deviations from the Boltzmann distribution for the first five vibrational levels of O2(v) were calculated, and the present study suggests that these deviations are not significant. It was found that the difference between the non-Boltzmann and Boltzmann distribution assumptions of O2(v) and the difference between ion and neutral temperature can lead to an increase of up to about 3 or a decrease of up to about 4 of the calculated NmF2 as a result of a respective increase or a decrease in K2. The IZMIRAN model reproduces major features of the data. We found that the inclusion of vibrationally excited N2(v > 0) and O2(v > 0) in the calculations improves the agreement between the calculated NmF2 and the data on 6, 9, and 10 April. However, both the daytime and nighttime densities are reproduced by the IZMIRAN model without the vibrationally excited nitrogen and oxygen on 8 and 11 April better than the IZMIRAN model with N2(v > 0) and O2(v > 0). This could be due to possible uncertainties in model neutral temperature and densities, EUV fluxes, rate coefficients, and the flow of ionization between the ionosphere and plasmasphere, and possible horizontal divergence of the flux of ionization above the station. Our calculations show that the increase in the O+ + N2 rate factor due to N2(v > 0) produces a 5-36 decrease in the calculated daytime peak density. The increase in the O++ O2 loss rate due to vibrational-ly excited O2 produces 8-46 reductions in NmF2. The effects of vibrationally excited O2 and N2 on Ne and Te are most pronounced during the daytime.Key words. Ion chemistry and composition · Ionosphere – atmosphere interactions · Ionospheric disturbances

Deactivation of vibrationally excited nitrogen molecules by collision with nitrogen atoms

1987 ◽  
Vol 91 (2) ◽  
pp. 312-314 ◽  
Author(s):  
A. Lagana ◽  
E. Garcia ◽  
L. Ciccarelli
Keyword(s):  
Vibrationally Excited ◽  
Excited Nitrogen

Vibrationally excited nitrogen in stable auroral red arcs and its effect on ionospheric recombination

1974 ◽  
Vol 79 (25) ◽  
pp. 3807-3818 ◽  
Author(s):  
George P. Newton ◽  
James C. G. Walker ◽  
P. H. E. Meijer
Keyword(s):  
Vibrationally Excited ◽  
Excited Nitrogen
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