THE REACTIVE COMPONENTS IN ACTIVE NITROGEN AND THE ROLE OF SPIN CONSERVATION IN ACTIVE NITROGEN REACTIONS

1956 ◽  
Vol 34 (9) ◽  
pp. 1217-1231 ◽  
Author(s):  
H. G. V. Evans ◽  
C. A. Winkler
Keyword(s):  
Experimental Information ◽  
Active Species ◽  
Convincing Evidence ◽  
Critical Examination ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
Electronically Excited ◽  
Excited Molecules ◽  
Triatomic Radicals

Critical examination of the available experimental information provides rather convincing evidence that atomic nitrogen is the main reactive species in active nitrogen. It appears quite unlikely that a significant contribution to the activity is made by electronically excited molecules, metastable atoms, ions, or triatomic radicals. Evidence exists, however, for the presence of more than one active species, and a plausible suggestion would seem to be that the second species is vibrationally excited molecules. Consideration of the role of spin conservation in reactions of active nitrogen leads to the conclusion that reactions that conserve spin occur more readily than those in which spin is not conserved.

The role of vibrationally excited molecules in the chemistry of the early Universe

2011 ◽  
Vol 22 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Savino Longo ◽  
Carla Maria Coppola ◽  
Daniele Galli ◽  
Francesco Palla ◽  
Mario Capitelli
Keyword(s):  
Early Universe ◽  
Vibrationally Excited ◽  
Excited Molecules

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.

CHEMICAL SCAVENGER PROBE STUDIES OF ATOM AND EXCITED MOLECULE REACTIVITY IN ACTIVE NITROGEN FROM A SUPERSONIC STREAM

1964 ◽  
Vol 42 (11) ◽  
pp. 2440-2450 ◽  
Author(s):  
A. Fontijn ◽  
D. E. Rosner ◽  
S. C. Kurzius
Keyword(s):  
Relative Concentration ◽  
Measurement Techniques ◽  
Supersonic Nozzle ◽  
Active Species ◽  
Discharge Zone ◽  
Supersonic Stream ◽  
Active Nitrogen ◽  
Local Composition ◽  
End Point ◽  
Excited Molecules

A quartz chemical scavenger probe has been developed to study the local composition of supersonic electrically discharged gas streams. The probe samples the central portion of a nonequilibrium jet and allows direct comparison with other local measurement techniques (e.g. differential catalytic detectors) for determining active species concentrations. Active nitrogen from a Mach 3 stream was sampled and reacted inside the probe with one of the scavenger gases NO, NH3, or C2H4 at 18.8 mm Hg and at an average temperature of 500 °K. Limiting values of the NO destruction rate and the HCN production rate were observed; however, NH3 destruction exhibited no plateau. The observed maximum rate of NO destruction was 2.1 times as large as the NO flow rate at the light titration end-point. This difference is attributed to a reaction of NO, added in excess of the titration end-point flow, with metastable electronically excited molecules formed within the discharge zone. The converging-diverging supersonic nozzle-glow discharge source used in these experiments apparently delivers metastable excited molecules to the reaction zone in a higher relative concentration than do the more conventional subsonic electrical discharge flow systems used for most previous active nitrogen studies.

CN Emission in Active Nitrogen. II. The Role of Energy Transfer and Atom Transfer Reactions in CN(X2Σ+) Excitation

1972 ◽  
Vol 50 (16) ◽  
pp. 2527-2536 ◽  
Author(s):  
G. M. Provencher ◽  
D. J. McKenney
Keyword(s):  
Energy Transfer ◽  
Ground State ◽  
Absolute Intensity ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
Band Emission ◽  
Electronically Excited ◽  
Order Of Magnitude ◽  
Three Body ◽  
A Minor

A simplified mechanism is presented for excitation of ground state CN(X2Σ+) formed from carbonaceous impurity in flowing N2 subjected to a microwave discharge. Analysis of absolute intensity data from spectrometer recordings of CN(B2Σ+ → X2Σ+) violet band emission enabled order of magnitude estimates of rate constants for CN(X2Σ+) excitation by energy transfer from vibrationally excited ground state nitrogen, [Formula: see text][Formula: see text]and formation of electronically excited NCN* in a three body reaction[Formula: see text]Energy transfer from [Formula: see text] is shown to be a minor source of excitation of CN to radiative levels. N2(A) is a source of vibrationally excited ground state nitrogen, [Formula: see text] which in turn excites CN. Vibrational population profiles under all conditions in this work are shown to be primarily a function of [Formula: see text] Evidence for the participation of the A2Π state of CN is shown in the population maxima at ν = 4 and 10 of the B2Σ+ state.

CATALYZED RECOMBINATION OF NITROGEN ATOMS, AND THE POSSIBLE PRESENCE OF A SECOND ACTIVE SPECIESIN ACTIVE NITROGEN

1960 ◽  
Vol 38 (12) ◽  
pp. 2514-2522 ◽  
Author(s):  
Roger Kelly ◽  
C. A. Winkler
Keyword(s):  
Rate Constant ◽  
Pressure Range ◽  
Order Rate Constant ◽  
Active Species ◽  
Third Order ◽  
Active Nitrogen ◽  
Atom Concentration ◽  
Order Rate ◽  
Excited Molecules ◽  
Atom Decay

The reactions of ethylene, ethane, and ammonia with active nitrogen have been studied over the pressure range 0.3 to 4 mm usinganunheatedreaction vessel. The object was to determine why each reactant shows, as is well-known, a smaller extent of reaction at lower temperatures than would be predicted from the atom concentration. It was concluded that ethylene probably brought about homogeneouscatalyzedrecombination, i.e. the process [Formula: see text] followed by N + N•C2H4 → N2 + C2H4. The over-all third-order rate constant appeared to be very large, about 1.8 × 10−28 cc2 molecule−2 sec−1. The behavior of ammonia was quite different from that of ethylene and it was, in fact, possible to show that the extent of reaction was not governed by the instantaneous atom concentration at all. The results can be explained qualitatively, however, if it is assumed that excited molecules formed in the course of homogeneous atom decay constitute a second active species in active nitrogen. This view serves also to explain the failure in such work as that of Kistiakowsky etal. to observe ammonia destruction or excited molecules when especially low atom concentrations are used. The few experiments involving ethane were sufficient to show that the reactivity was low for a different reason than with ethylene.

Pure-Beams" of Highly Vibrationally Excited Molecules"

2002 ◽  
Author(s):  
Alec M. Wodtke
Keyword(s):  
Vibrationally Excited ◽  
Excited Molecules
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