The photochemical decomposition of chlorine dioxide in carbon tetrachloride solution

1931 ◽  
Vol 27 ◽  
pp. 508 ◽  
Author(s):  
Y. Nagai ◽  
C. F. Goodeve
1937 ◽  
Vol 15b (12) ◽  
pp. 499-524 ◽  
Author(s):  
J. W. T. Spinks ◽  
H. Taube

Insolation of carbon tetrachloride solutions of chlorine dioxide initiates a thermal decomposition, the magnitude of which may exceed that for the photoreaction with low light intensity. This thermal decomposition is inhibited by keeping the solutions at 3 °C. or by adding water.In contradiction to the findings of other investigators, it is found that chlorine and oxygen are not the only products of photodecomposition. As products of the photodecomposition of chlorine dioxide at the wave-lengths 3650 and 4360 Å, the oxides Cl2O, Cl2O6, and Cl2O7 as well as chlorine and oxygen appear. The quantum efficiency at λ 3650 Å is 2, and at 4360 Å, 1.In the unsensitized decomposition, concentration effects are observed which are greatly decreased when the solutions are stirred.In the bromine sensitized decomposition with 5460 Å, there is less chlorine monoxide but relatively as much Cl2O6 and Cl2O7 formed as in the unsensitized reaction.In the sensitized decomposition the quantum yield is independent of the concentration of chlorine dioxide, but depends on the light intensity. The observed quantum yield for the sensitized reaction is 0.2 to 0.3.Mechanisms for the photo-reactions have been proposed.


The photochemical decomposition of dicumyl peroxide and cumene hydroperoxide in the absence of oxygen has been investigated in two solvents. Reaction mechanisms have been suggested from a consideration of the products and the quantum yields. Dicumyl peroxide forms αα '-dimethyl benzyl alcohol exclusively at 3130 Å in n -hexane. At 2537 Å a little acetophenone is also formed. In carbon tetrachloride solution the product at 3130 Å is acetophenone and at 2537 Å a mixture of acetone and acetophenone is formed. In n -hexane the main product from cumene hydroperoxide is αα '-dimethyl benzyl alcohol. In carbon tetrachloride on the other hand acetone and acetophenone and a dark polymer are formed. For cumene hydroperoxide in n -hexane at 3130 Å the quantum yield is 1⋅57 at 20°C, the chain reaction being sustained by radicals formed from the solvent. In carbon tetrachloride solution the quantum yield is 0⋅75.


1949 ◽  
Vol 17 (6) ◽  
pp. 566-573 ◽  
Author(s):  
T. L. Batke ◽  
L. M. Dorfman ◽  
D. J. LeRoy

2002 ◽  
Vol 17 (1) ◽  
pp. 214-223 ◽  
Author(s):  
Masaki Narisawa ◽  
Takeshi Hasegawa ◽  
Kiyohito Okamura ◽  
Masayoshi Itoh ◽  
Thomas Apple ◽  
...  

Polyvinylsilane (PVS), derived from vinylsilane by radical polymerization, was partially oxidized in hot carbon tetrachloride solution by flowing air. If the air flow time is adjusted, soft gel films can be formed in a Teflon dish by casting the PVS solution. After the PVS films were peeled from the substrates, they were pyrolyzed at various temperatures. Spectroscopic studies of the pyrolyzed films up to 1273 K suggested that carbosilane (Si–CH2–Si) structures are formed in the films at 473–673 K. The compositions of the amorphous films obtained at 1673 K were approximately SiC1.38O0.21 and SiC1.41O0.51, depending on the crosslinking conditions. The oxygen incorporated in the films was removed in the form of CO and SiO during further heating at 1673–1873 K. The compositions of the films were changed to approximately SiC1.25 and SiC1.26, respectively, at 2073 K. The films obtained at 1273 K did not show degradation during the oxidation at 1273–1673 K while a protective silica layer was formed on their surfaces.


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