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.

THE RATE OF REACTION OF ACTIVE NITROGEN WITH AMMONIA AND ETHYLENE

1962 ◽  
Vol 40 (1) ◽  
pp. 5-14 ◽  
Author(s):  
A. N. Wright ◽  
C. A. Winkler
Keyword(s):  
Gas Phase ◽  
Rate Constant ◽  
Reaction Times ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Initial Flow ◽  
Flow Rates ◽  
Average Value ◽  
Rate Of Reaction ◽  
Excited Nitrogen

The rate constants for the reactions of C2H4 and NH3 are determined by termination of the reactions in the gas phase after different times of reaction. The average value for the rate constant of the N atom–C2H4 reaction at 150 °C is 1.8 × 1010 cc mole−1 sec−1, when the initial N-atom concentration is determined from the maximum production of HCN. The average value for the rate constant for the over-all reaction of NH3 with excited nitrogen molecules, at 104 °C in the "poisoned" system, and 83 °C in the "unpoisoned" system, for low initial flow rates of NH3, or short reaction time, is 2.2 × 1010 cc mole−1 sec−1. The decrease in value of this rate constant at higher initial flow rates of NH3 and longer reaction times in the "poisoned" system indicates that the species responsible for NH3 decomposition is generated during the decay of N atoms in the presence of NH3. The value for the NH3 reaction is discussed in terms of energy transfer.

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.

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 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.

scholarly journals Influence of Active Nitrogen Species on the Nitridation Rate of Sapphire

1998 ◽  
Vol 537 ◽  
Author(s):  
A.J. Ptak ◽  
K.S. Ziemer ◽  
M.R. Millecchia ◽  
C.D. Stinespring ◽  
T.H. Myers
Keyword(s):  
Molecular Nitrogen ◽  
Active Species ◽  
Operating Conditions ◽  
Rf Plasma ◽  
Atomic Nitrogen ◽  
Active Nitrogen ◽  
Plasma Sources ◽  
Electrostatic Deflector ◽  
Low Energy Ions ◽  
Operating Regimes

AbstractThe operating regimes of two rf-plasma sources, an Oxford CARS-25 and an EPI Unibulb, have been extensively characterized. By changing the exit aperture configuration and using an electrostatic deflector, the Oxford source could produce either primarily atomic nitrogen, atomic nitrogen mixed with low energy ions, or a large flux of higher energy ions (>65eV) as the active species in a background of neutral molecular nitrogen. The EPI source produced a significant flux of metastable molecular nitrogen as the active species with a smaller atomic nitrogen component. Nitridation of sapphire using each source under the various operating conditions indicate that the reactivity was different for each type of active nitrogen. Boron contamination originating from the pyrolytic boron nitride plasma cell liner was observed.

Evidence of Multiple Trapping Sites for Excited Nitrogen Atoms in Solid Molecular Nitrogen

1961 ◽  
Vol 34 (3) ◽  
pp. 948-957 ◽  
Author(s):  
R. A. Hemstreet ◽  
J. R. Hamilton
Keyword(s):  
Molecular Nitrogen ◽  
Multiple Trapping ◽  
Excited Nitrogen ◽  
Trapping Sites

scholarly journals Quantum analysis of the rotational structure of the first positive bands of nitrogen (N 2 )

1932 ◽  
Vol 136 (829) ◽  
pp. 114-144 ◽  
Keyword(s):  
Electronic Configuration ◽  
Selective Excitation ◽  
Nitrogen Molecule ◽  
Rotational Structure ◽  
Positive System ◽  
Initial State ◽  
Final State ◽  
Active Nitrogen ◽  
Quantum Analysis ◽  
Vibrational Levels

The greenish-yellow afterglow of active nitrogen was first described, by Lewis. Two decades have passed since Fowler and Strutt showed that this afterglow was due to a selective excitation of a few green, yellow and red bands belonging to the first positive system of the nitrogen molecule (N 2 ). Recent work on active nitrogen indicates that the selective excitation is due to metastable nitrogen atoms giving up their energy to metastable nitrogen molecules in state A, the final state of the first positive bands, thus leading to the selective excitation of certain specific vibrational levels in state B, the initial state of the first positive bands. The molecule then returns to state A, at the same time emitting the bands which constitute the afterglow. From the rotational analysis of the second positive nitrogen bands by Lindau, and Hulthèn and Johansson, it is known that state B corresponds to a 3 II state, the second positive bands having their final state in common with the initial state of the first positive bands. No definite information has been found concerning the electronic configuration of the nitrogen molecule which gives rise to state A. This can be obtained by making a detailed analysis of the rotational structure of the first positive nitrogen bands.

Kinetics of reactions involving CN emission III. The excitation of CN in active nitrogen

1968 ◽  
Vol 305 (1480) ◽  
pp. 93-105 ◽  
Keyword(s):  
Ground State ◽  
Blue Emission ◽  
Absolute Intensity ◽  
Active Species ◽  
Active Nitrogen ◽  
System A ◽  
Vibrational Levels ◽  
Similar Quantity ◽  
Kinetics Of ◽  
Cn Radicals

The presence of carbonaceous impurities in active nitrogen causes strong blue CN emission from levels of the B 2 ∑ + state up to v ' = 15. The kinetics of this emission have been studied, and the concentrations of CN radicals measured by electronic absorption spectroscopy, in systems where the blue emission was induced by adding traces of methane before the discharge, or a similar quantity of acetylene after the discharge and examining the system a long way downstream. CN is shown to be excited by energetic species formed in nitrogen atom recombination. The absolute intensity of the emission and its kinetics suggest that lower vibrational levels of the metastable A 3 ∑ + state of N 2 are mainly responsible, but the kinetics of quenching by ammonia and water for nitrogen and argon carriers show that an additional active species is present, probably N 2 in high vibrational levels of the ground state.

INTENSITIES OF EMISSION LINES IN FLAMES OF METAL HALIDES WITH ACTIVE NITROGEN

1963 ◽  
Vol 41 (8) ◽  
pp. 2060-2066 ◽  
Author(s):  
L. F. Phillips
Keyword(s):  
Energy Transfer ◽  
Energy Transfer Process ◽  
Nitrogen Molecule ◽  
Spectral Lines ◽  
Emission Lines ◽  
Metal Halides ◽  
Kcal Mole ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Excitation Mechanisms

The intensities of spectral lines emitted by flames of a number of metal halides with active nitrogen have been found to vary as the square of the nitrogen atom concentration. When the total energy required for simultaneous dissociation of the halide and excitation of the metal atom is less than about 200 kcal/mole the energy transfer process is too efficient to be attributed to the termolecular reaction of a halide molecule with a pair of nitrogen atoms. The observations are consistent with the hypothesis that in this case energy is transferred to the halide molecule during collision with a nitrogen molecule in the 5Σg+ state. Possible excitation mechanisms are discussed for less intense lines which would require up to 276 kcal/mole for simultaneous dissociation and excitation.

NITRIC OXIDE DECOMPOSITION INDUCED BY EXCITED NITROGEN MOLECULES IN ACTIVE NITROGEN

1962 ◽  
Vol 66 (9) ◽  
pp. 1747-1748 ◽  
Author(s):  
A. N. Wright ◽  
C. A. Winkler
Keyword(s):  
Nitric Oxide ◽  
Active Nitrogen ◽  
Nitric Oxide Decomposition ◽  
Oxide Decomposition ◽  
Excited Nitrogen
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