The reaction of cyanogen radicals with nitric oxide

1965 ◽  
Vol 283 (1394) ◽  
pp. 291-301 ◽  
Keyword(s):  
Nitric Oxide ◽  
Chemical Reaction ◽  
Vibrational Energy ◽  
Vibrational Excitation ◽  
Resonance Energy ◽  
Ultra Violet ◽  
Vibrationally Excited ◽  
Near Resonance ◽  
Continuous Absorption ◽  
Unstable Compound

Vibrational energy transfer and a chemical reaction between nitric oxide and the cyanogen radical have been studied by flash photolysing cyanogen and cyanogen bromide in the presence of nitric oxide. The product of the chemical reaction is, at least in part, the unstable compound nitrosyl cyanide NOCN and the rate constant is 2 x 10 12 ml. mole -1 s -1 or 1 x 10 17 ml. mole -2 s -1 with nitrogen as third body. The compound has a continuous absorption in the ultra-violet and yields vibrationally excited nitric oxide on photolysis. Vibrationally excited cyanogen radicals produced by means of electronic excitation of the radical produce vibrational excitation of the nitric oxide through near resonance energy exchange. Vibrational equilibrium is reached by nitric oxide through further resonance exchanges: CN + NO → NOCN, NOCN + hv → N O ( v > 0) + CN, NO ( v = 0) + CN ( v = n ) → NO ( v = 1) + CN ( v = n – 1 ) , NO ( v = 1) + CN ( v = m ) → NO ( v = 2) + CN ( v = m –1 ), 2NO { v = 1) ⇌ NO ( v = 2) + NO ( v = 0), NO ( v = 2) +NO ( v = 1) ⇌ NO ( v = 3) + NO { v = 0), etc.

The absorption spectrum of SO and the flash photolysis of sulphur dioxide and sulphur trioxide

1959 ◽  
Vol 249 (1259) ◽  
pp. 498-512 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Dissociation Energy ◽  
Sulphur Dioxide ◽  
Flash Photolysis ◽  
Ultra Violet ◽  
Vibrationally Excited ◽  
A Value ◽  
Continuous Absorption ◽  
Sulphur Trioxide ◽  
Normal Spectrum

The flash photolysis of sulphur dioxide under adiabatic conditions results in the complete temporary disappearance of its spectrum , which then slowly regains its original intensity over a period of several milliseconds. Simultaneously with the disappearance of the sulphur dioxide spectrum a continuous absorption appears in the far ultra-violet and fades slowly as the sulphur dioxide reappears. It is shown that the effect of the flash is thermal rather than photochemical, and the possibility of the existence of an isomer of sulphur dioxide at high temperatures is discussed; the disappearance of the normal spectrum on flashing is explained in this way. Several previously unrecorded bands of SO observed in the photolysis indicate that the vibrational numbering of its spectrum should be revised by the addition of 2 to the present values of v' . This leads to a value of the dissociation energy of 123.5 kcal. In formation about the levels v' = 4, 5 and 6 has also been obtained. The isothermal flash photolysis of sulphur trioxide results in the appearance of vibrationally excited SO, and the primary photochemical step in this reaction is discussed.

Energy disequilibrium in the flash photolysis of NO 2

1973 ◽  
Vol 334 (1599) ◽  
pp. 553-568 ◽  
Keyword(s):  
Nitric Oxide ◽  
Flash Photolysis ◽  
Vibrational Energy ◽  
Dissociation Limit ◽  
Primary Process ◽  
Transfer Energy ◽  
Vibrationally Excited ◽  
Absolute Concentrations ◽  
The Absolute ◽  
Excited Oxygen

From measurements of the absolute concentrations of vibrationally excited oxygen produced in levels v" = 4 to v" = 13, it is concluded that ca . 20 % of the exothermicity of the reaction O( 3 P) + NO 2 → NO + O + 2 ( v" ≤11) (1) appears initially as vibrational energy in oxygen. Vibrationally excited nitric oxide ( v" = 1, 2) is also observed and may be produced in this reaction or in the primary process NO 2 + hv → NO ( v" ≤ 2) + O( 3 P). More highly excited oxygen ( v" ≤ 15), with energy exceeding the exothermicity of the reaction, is produced in reaction (1) when the NO 2 is first excited by radiation above the dissociation limit near 400 nm. The excited NO 2 thus produced can also transfer energy to nitric oxide. NO 2 * + NO( v" = 0) → NO 2 + NO( v" = 1).

The study of energy transfer by kinetic spectroscopy I. The production of vibrationally excited oxygen

1956 ◽  
Vol 233 (1195) ◽  
pp. 455-464 ◽  
Keyword(s):  
Flash Photolysis ◽  
Vibrational Energy ◽  
Vibrationally Excited ◽  
Near Resonance ◽  
Vibrational Levels ◽  
Great Excess ◽  
First Time ◽  
Kinetics Of ◽  
Excited Oxygen ◽  
Electronic Ground

The flash photolysis of chlorine dioxide or of nitrogen dioxide in a great excess of inert gasyields oxygen molecules in their electronic ground states with up to eight quanta of vibrational energy. By a study of the reaction kinetics of the two systems, it is concluded that these excited molecules have their origin in the reactions O + NO 2 = NO + O 2 and O + CIO 2 = CIO + O 2 respectively. Thus, for the first time we have available a very convenient method of studying the collisional transfer and degradation of vibrational energy from molecules in the higher vibrational levels of the ground state and some preliminary measurements of the efficiency of deactivation by various molecules are given. It is concluded that the energy is removed most readily either when there is near resonance of the vibrational levels with those of the oxygen, or by free radicals. Some of the reactions of the chlorine oxides present are also discussed.

Vibrationally excited nitric oxide produced in the flash photolysis of nitrosyl halides

1962 ◽  
Vol 268 (1334) ◽  
pp. 291-303 ◽  
Keyword(s):  
Nitric Oxide ◽  
Energy Transfer ◽  
Ground State ◽  
Vibrational Relaxation ◽  
Direct Evidence ◽  
Flash Photolysis ◽  
Vibrational Energy ◽  
Electronic States ◽  
Vibrationally Excited ◽  
Direct Production

The flash photolysis of nitrosyl chloride and nitrosyl bromide has been studied under isothermal conditions. Vibrationally excited nitric oxide molecules were produced and all levels from v " = 0 to v " = 11 were observed in absorption from the ground electronic states in the β, γ, δ and Є systems. Some of these bands have not previously been reported. The mechanism of the production is either directly NO R + hv → NO ( X 2 II , v ≤ 11) + R ( 2 P ), or by the sequence which includes the reactions NO R + hv → NO( 4 II ) + R , NO. 4 II + M → NO ( X 2 II , v > 0) + M In the latter case, the 4 II state of NO lies not more than 3·5 eV above the ground state. Other possible mechanisms and models accounting for the direct production of vibrationally excited NO in its ground electronic states are discussed. By flashing chlorine in the presence of NOCl it was shown that the reaction Cl + NOCl → Cl 2 + NO ( v > 0) does not occur, thus providing direct evidence that in reactions of the type A + BCD → AB + CD only the AB molecule containing the newly formed bond can be vibrationally excited. Vibrational relaxation is very rapid and probably occurs by step-wise degradation involving resonance vibrational energy transfer. NOCl and NOBr are very efficient and with NO itself the reaction NO ( v = n ) + NO ( v = 0) → NO ( v = n -1) + NO ( v = 1) can be followed.

scholarly journals The calculation of TV, VT, VV, VV' − rate coefficients for the collisions of the main atmospheric components

1998 ◽  
Vol 16 (7) ◽  
pp. 838-846 ◽  
Author(s):  
A. S. Kirillov
Keyword(s):  
Experimental Data ◽  
Energy Transfer ◽  
Vibrational Energy ◽  
Relaxation Times ◽  
Atmospheric Composition ◽  
Rate Coefficients ◽  
Frequency Change ◽  
Vibrational Energy Transfer ◽  
Ion Chemistry ◽  
Vibrationally Excited

Abstract. The first-order perturbation approximation is applied to calculate the rate coefficients of vibrational energy transfer in collisions involving vibrationally excited molecules in the absence of non-adiabatic transitions. The factors of molecular attraction, oscillator frequency change, anharmonicity, 3-dimensionality and quasiclassical motion have been taken into account in the approximation. The analytical expressions presented have been normalized on experimental data of VT-relaxation times in N2 and O2 to obtain the steric factors and the extent of repulsive exchange potentials in collisions N2-N2 and O2-O2. The approach was applied to calculate the rate coefficients of vibrational-vibrational energy transfer in the collisions N2-N2, O2-O2 and N2-O2. It is shown that there is good agreement between our calculations and experimental data for all cases of energy transfer considered.Key words. Ionosphere (Auroral ionosphere; ion chemistry and composition). Atmospheric composition and structure (Aciglow and aurora).

Towards Vibrationally Excited Nitric Oxide Monitoring (VENOM) in a Laminar, Hypersonic Boundary Layer

2020 ◽  
Author(s):  
Zachary D. Buen ◽  
Casey Broslawski ◽  
Madeline Smotzer ◽  
Jason E. Kuszynski ◽  
Simon North ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Boundary Layer ◽  
Hypersonic Boundary Layer ◽  
Vibrationally Excited

scholarly journals VI. On the spectra of the compounds of carbon with hydro­gen and nitrogen. No. II

1880 ◽  
Vol 30 (200-205) ◽  
pp. 494-509 ◽  
Keyword(s):  
Nitric Oxide ◽  
Carbonic Acid ◽  
Carbon Disulphide ◽  
Ultra Violet ◽  
Hydrocyanic Acid ◽  
Atmospheric Air

In our last communication on this subject ( ante , p. 152), we thus summarised the results of our observations as to the " nitrocarbon spectrum.” " On a review of the whole series of observations, certain points stand out plainly In the first place, the seven blue, the violet, and ultra-violet bands, characteristic of the flame of cyanogen are conspicuous in the arc taken in an atmosphere of nitrogen, air, nitric oxide, or ammonia, and they disappear, almost, if not quite, when the arc is taken in a non-nitrogenous atmosphere of hydrogen, carbonic oxide, carbonic acid, or chlorine. These same bands are seen brightly in the flames of cyanogen and hydrocyanic acid, but are not seen in those of hydrocarbons, carbonic oxide, or carbon disulphide. The conclusion seems irresistible that they belong to cyanogen ; and this conclusion does not seem to us at all invalidated by the fact that they are seen weakly, or by flashes, in the arc or spark taken in gases supposed free from nitrogen, by reason of the extreme difficulty of removing the last traces of air. They are never, in such a case, the principal or prominent part of the spectrum, and in a continuous experiment they are seen to fade out in proportion as the nitrogen is removed. This conclusion is strengthened by the observations of one of us, that cyanogen (or hydrocyanic acid) is generated in the arc m atmospheric air in large quantity."

Sign in / Sign up

Export Citation Format

Share Document