Reaction of excited oxygen atoms with nitrous oxide. Rate constants for reaction of ozone with nitric oxide and with nitrogen dioxide

1973 ◽  
Vol 77 (11) ◽  
pp. 1341-1345 ◽  
Author(s):  
J. A. Ghormley ◽  
R. L. Ellsworth ◽  
C. J. Hochanadel

1978 ◽  
Vol 56 (23) ◽  
pp. 2934-2939 ◽  
Author(s):  
D. L. Singleton ◽  
R. J. Cvetanović

Rate constants for the reactions O(3P) + HX → OH + X (X = Br, I) have been determined by a phase shift technique. Oxygen atoms were generated by modulated mercury photosensitized decomposition of nitrous oxide, and were monitored by the chemiluminescence from the reaction with nitric oxide. Over the temperature interval 298–554 K, the rate constants are satisfactorily represented by the Arrhenius expressions kO+HBr = (8.09 ± 0.86) × 109 exp (−3.59 ± 0.08)/RT and kO+HI = (2.82 ± 0.27) × 1010 exp (−1.99 ± 0.07)/RT, where the units are ℓ mol−1 s−1 and kcal mol−1. The indicated uncertainties are one standard deviation. The results of bond energy–bond order calculations, incorporating recently proposed modifications, are discussed.



1959 ◽  
Vol 37 (5) ◽  
pp. 953-965 ◽  
Author(s):  
S. Sato ◽  
R. J. Cvetanović

The effect of the presence of nitrogen, oxygen, and nitric oxide on the reaction between cis-2-pentene and oxygen atoms has been investigated at room temperature (25 ± 2 °C). For production of oxygen atoms use was made of mercury-photosensitized decomposition of nitrous oxide and of the photolysis of nitrogen dioxide at 3660 Å.In the N2O work, the presence of molecular oxygen induced the formation of acetaldehyde, propanal, methanol, and ethanol. In the NO2 work, the amounts of acetaldehyde, propanal, and ethyl nitrate formed increased rapidly with increasing pressure of molecular oxygen. Possible reaction mechanisms for the formation of these compounds are discussed.Additional information was obtained on the pressure-independent fragmentation in the reaction of oxygen atoms with cis-2-pentene.



1979 ◽  
Vol 57 (9) ◽  
pp. 949-952 ◽  
Author(s):  
W. S. Nip ◽  
D. L. Singleton ◽  
R. J. Cvetanović

Rate constants were determined for the reactions of O(3P) atoms with allene and with 1,3-butadiene by a phase shift technique in which oxygen atoms were generated by modulated mercury photosensitized decomposition of nitrous oxide and monitored by the chemiluminescence from their reaction with NO. Over the temperature interval 297–574 K, the Arrhenius equation for the O(3P) + allene reaction is k1A = (2.99 ± 0.41) × 10−11 exp [(−941 ± 54)/T] cm3 molecule−1 s−1, where the indicated uncertainties are 95% confidence limits. At 299 and 488 K, the rate constant for O(3P) + 1,3-butadiene is essentially the same, within 10%, with an average value of 2.07 × 10−11 cm3 molecule−1 s−1.



1969 ◽  
Vol 14 (2) ◽  
pp. 181-189 ◽  
Author(s):  
H.Edward Mishmash ◽  
Clifton E. Meloan


1955 ◽  
Vol 33 (5) ◽  
pp. 843-848
Author(s):  
T. M. Rohr ◽  
W. Albert Noyes Jr.

The addition of ethane to nitrogen dioxide either during exposure to radiation transmitted by pyrex, or afterwards, reduces the amount of oxygen formed. At room temperature this is apparently due to the effectiveness of ethane in promoting the reverse reaction of nitric oxide and oxygen to form nitrogen dioxide. At temperatures over 100° there is a reaction which uses oxygen atoms produced in the primary process. Nitroethane (or nitrosoethane) is formed along with carbon monoxide, carbon dioxide, and some methane. The results suggest that acetaldehyde is an intermediate, but acetaldehyde could not be detected because it would react thermally with nitrogen dioxide. It is not possible to give a complete explanation of the results, but suggestions can be made which might form the basis for later work.



1995 ◽  
Vol 82 (5) ◽  
pp. 1246-1254 ◽  
Author(s):  
Masaji Nishimura ◽  
Dean Hess ◽  
Robert M. Kacmarek ◽  
Ray Ritz ◽  
William E. Hurford

Background Inhaled nitric oxide (NO) may be useful in the treatment of adult respiratory distress syndrome and other diseases characterized by pulmonary hypertension and hypoxemia. NO is rapidly converted to nitrogen dioxide (NO2) in oxygen (O2) environments. We hypothesized that in patients whose lungs are mechanically ventilated and in those with a long residence time for NO in the lungs, a clinically important [NO2] may be present. We therefore determined the rate constants for NO conversion in adult mechanical ventilators and in a test lung simulating prolonged intrapulmonary residence of NO. Methods NO (800 ppm) was blended with nitrogen (N2), delivered to the high-pressure air inlet of a Puritan-Bennett 7200ae or Siemens Servo 900C ventilator, and used to ventilate a test lung. The ventilator settings were varied: minute ventilation (VE) from 5 to 25 l/min, inspired O2 fraction (FIO2) from 0.24 to 0.87, and [NO] from 10 to 80 ppm. The experiment was then repeated with air instead of N2 as the dilution gas. The effect of pulmonary residence time on NO2 production was examined at test lung volumes of 0.5-4.0 l, VE of 5-25 l/min, FIO2 of 0.24-0.87, and [NO] of 10-80 ppm. The inspiratory gas mixture was sampled 20 cm from the Y-piece and from within the test lung. NO and NO2 were measured by chemiluminescence. The rate constant (k) for the conversion of NO to NO2 was determined from the relation 1/[NO]t-1/[NO]o = k x [O2] x t, where t = residence time. Results No NO2 was detected during any trial with VE 20 or 25 l/min. With N2 dilution and the Puritan-Bennett 7200ae, NO2 (< or = 1 ppm) was detected only at a VE of 5 l/min with an FIO2 of 0.87 and [NO] > or = 70 ppm. In contrast, [NO2] values were greater with the Servo 900C ventilator than with the Puritan-Bennett 7200ae at similar settings. When NO was diluted with air, clinically important [NO2] values were measured with both ventilators at high [NO] and FIO2. Rate constants were 1.46 x 10(-9) ppm-2.min-1 when NO was mixed with N2, 1.17 x 10(-8) ppm-2.min-1 when NO was blended with air, and 1.44 x 10(-9) ppm-2.min-1 in the test lung. Conclusions [NO2] increased with increased FIO2 and [NO], decreased VE, blending with air, and increased lung volumes. Higher [NO2] was produced with the Servo 900C ventilator than the Puritan-Bennett 7200ae because of the greater residence time. With long intrapulmonary residence times for NO, there is a potential for NO2 production within the lungs. The rate constants determined can be used to estimate [NO2] in adult mechanical ventilation systems.





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