A quantitative study of alkyl radical reactions by kinetic spectroscopy. IV. The flash photolysis of azopropanes

1981 ◽  
Vol 13 (4) ◽  
pp. 367-384 ◽  
Author(s):  
Hiroyuki Adachi ◽  
Norman Basco

The explosive oxidation of acetylene, initiated homogeneously by the flash photolysis of a small quantity of nitrogen dioxide, has been investigated by flash spectroscopy. The absorption spectra of OH, CH, C 2 (singlet and triplet), C 3 , CN and NH, a number of which have not previously been observed, are described, and the relative concentrations, at all times throughout the explosion, are given. Four stages have been distinguished in the explosive reaction: 1. An initial period during which only OH appears. 2. A rapid chain branching involving all the diatomic radicals. 3. Further reaction, occurring only when oxygen is present in excess of equimolecular proportions, during which the OH concentration rises exponentially and the other radicals are totally consumed. 4. A relatively slow exponential decay of the excess radical concentration remaining after completion of stages 2 and 3. The duration of stage 1 is 0 to 3 ms. In an equimolecular mixture at 20 mm total pressure, containing 1.5 mm NO 2 , the durations of both stage 2 and stage 3 are approximately 10 -4 s and the half-life of OH in stage 4 is 0.28 ms. A preliminary interpretation of these changes and of the radical reactions is given.


1971 ◽  
Vol 49 (10) ◽  
pp. 1659-1664 ◽  
Author(s):  
R. W. Fair ◽  
A. Van Roodselaar ◽  
O. P. Strausz

The rate constant of the reaction of ground state S(3P) atoms with molecular oxygen, S(3P) + O2(X3Σg−) → SO(X3Σ−) + O(3P), has been determined as (1.7 ± 0.2) × 1012 cm3 mol−s− at 298 °K by means of kinetic spectroscopy in the vacuum ultraviolet region. The source of S(3P) atoms was the isothermal flash photolysis of COS in the presence of Ar or CO2.


2004 ◽  
Vol 43 (27) ◽  
pp. 3598-3601 ◽  
Author(s):  
Luisa Benati ◽  
Rino Leardini ◽  
Matteo Minozzi ◽  
Daniele Nanni ◽  
Rosanna Scialpi ◽  
...  

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