THE MERCURY PHOTOSENSITIZED REACTIONS OF NITRIC OXIDE

1952 ◽  
Vol 30 (3) ◽  
pp. 194-202 ◽  
Author(s):  
J. D. Mcgilvery ◽  
C. A. Winkler
Keyword(s):  
Nitric Oxide ◽  
Vapor Pressure ◽  
Pressure Range ◽  
Mercury Vapor ◽  
Low Pressure ◽  
Primary Process ◽  
Light Filters ◽  
Photochemical Decomposition ◽  
Mercury Vapor Pressure ◽  
Oxygen Atoms

The photochemical decomposition of nitric oxide has been studied over a pressure range 60 to 500 mm., using a low pressure mercury arc source and a circulating system. Stoichiometrically, the reaction was found to be represented by 6NO → N2 + 2N2O3. Addition of nitrogen decreased the rate, as did also a decrease in the mercury vapor pressure. Using appropriate light filters at 1.7 × 10−3 mm. mercury pressure the decomposition was shown to be photosensitized by Hg (61P1) atoms. The primary process is probably dissociation of nitric oxide into nitrogen and oxygen atoms.

PRELIMINARY STUDY OF PHOTOCHEMICAL BEHAVIOR IN THE SYSTEM NITROGEN DIOXIDE – ETHANE

1955 ◽  
Vol 33 (5) ◽  
pp. 843-848
Author(s):  
T. M. Rohr ◽  
W. Albert Noyes Jr.
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Nitrogen Dioxide ◽  
Room Temperature ◽  
Reverse Reaction ◽  
Primary Process ◽  
Photochemical Behavior ◽  
Preliminary Study ◽  
Oxygen Atoms

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.

Reactions of thiyl radicals. II. The photolysis of methyl disulfide vapor

1967 ◽  
Vol 45 (12) ◽  
pp. 1369-1374 ◽  
Author(s):  
P. M. Rao ◽  
J. A. Copeck ◽  
A. R. Knight
Keyword(s):  
Nitric Oxide ◽  
Activation Energy ◽  
Apparent Activation Energy ◽  
Pressure Range ◽  
Excess Energy ◽  
Inert Gases ◽  
Effect Of Temperature ◽  
Primary Process ◽  
Direct Production ◽  
Thiyl Radicals

The photolysis of methyl disulfide vapor in the pressure range 2–25 Torr at wavelengths between 2 300 and 2 800 and at 2 288 Å has been examined and the effect of temperature, pressure, added inert gases, ethyl disulfide, and nitric oxide determined.The primary process is a direct production of two CH3S radicals which have excess energy and which can be observed as methyl thionitrite when NO is present during the decomposition. When pure disulfide is photolyzed the major observable product is methanethiol, although this material accounts for only a small fraction of the primarily produced thiyl radicals whose principal fate is recombination in a substrate-reforming reaction producing excited disulfide molecules. The latter species are deactivated by added gases, or by the substrate itself. The mode of mercaptan formation is by abstraction of H atoms from the substrate by excited CH3S radicals with an apparent activation energy of 1.5 kcal.

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