Primary Quantum Yield for the Dissociation of Iodine Molecules in Carbon Tetrachloride Solution and the Rate Constant for the Recombination Reaction1

1957 ◽  
Vol 79 (9) ◽  
pp. 2098-2102 ◽  
Author(s):  
R. L. Strong ◽  
J. E. Willard
Keyword(s):  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Rate Constant ◽  
Carbon Tetrachloride Solution

THE PHOTODECOMPOSITION OF CHLORINE DIOXIDE IN CARBON TETRACHLORIDE SOLUTION

1937 ◽  
Vol 15b (12) ◽  
pp. 499-524 ◽  
Author(s):  
J. W. T. Spinks ◽  
H. Taube
Keyword(s):  
Thermal Decomposition ◽  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Light Intensity ◽  
Quantum Efficiency ◽  
Chlorine Dioxide ◽  
Concentration Effects ◽  
Low Light ◽  
Carbon Tetrachloride Solution ◽  
Chlorine Monoxide

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.

DICHLORINE HEXOXIDE

1938 ◽  
Vol 16b (11) ◽  
pp. 382-389 ◽  
Author(s):  
M. H. Kalina ◽  
J. W. T. Spinks
Keyword(s):  
Molecular Weight ◽  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Physical Properties ◽  
Extinction Coefficient ◽  
Quantitative Estimation ◽  
Wave Length ◽  
Colorimetric Method ◽  
Green Light ◽  
Carbon Tetrachloride Solution

Some chemical and physical properties of dichlorine hexoxide are described and attention is drawn to its dangerous property of exploding violently on contact with organic substances.The extinction coefficient of solutions of dichlorine hexoxide in carbon tetrachloride solution for a wave-length of 5460 Å has been measured and found to be 2.4, which is very much less than that of liquid dichlorine hexoxide for the same wave-length. A colorimetric method is described for the quantitative estimation of dichlorine hexoxide in solutions. The molecular weight of dichlorine hexoxide in carbon tetrachloride solution has been redetermined, and it confirms the formula Cl2O6.Solutions of dichlorine hexoxide in carbon tetrachloride are decomposed photochemically by green light. Gaseous chlorine trioxide (ClO3) is decomposed photochemically by λ3650. Its decomposition is photosensitized by chlorine and bromine, the quantum yield in the chlorine sensitized reaction being about 1.

Photolysis of Di-tert-butyl Peroxide in Solution

1974 ◽  
Vol 52 (13) ◽  
pp. 2491-2492 ◽  
Author(s):  
Eduardo Lissi
Keyword(s):  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Gas Phase ◽  
Hydrocarbon Concentration ◽  
Tert Butyl ◽  
Carbon Tetrachloride Solution ◽  
Butyl Peroxide ◽  
Peroxide Molecule

Di-tert-butyl peroxide has been photolyzed at 3130 Å in carbon tetrachloride solution in the presence of cyclohexane. The quantum yield of free tert-butoxy radicals was 1.9 ± 0.1, independent of the hydrocarbon concentration. Unlike results obtained in the gas phase at 2537 Å, no evidence for the quenching of the excited peroxide molecule could be detected.

The photochemical decomposition of dicumyl peroxide and cumene hydroperoxide in solution

1956 ◽  
Vol 237 (1211) ◽  
pp. 464-475 ◽  
Keyword(s):  
Carbon Tetrachloride ◽  
Quantum Yield ◽  
Benzyl Alcohol ◽  
Main Product ◽  
Cumene Hydroperoxide ◽  
Quantum Yields ◽  
Dicumyl Peroxide ◽  
Carbon Tetrachloride Solution ◽  
Dimethyl Benzyl ◽  
Photochemical Decomposition

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.

The Photo‐Chlorination of Methyl Chloroformate in Carbon Tetrachloride Solution

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

Synthesis of Silicon Carbide Films from Partially Oxidized Polyvinylsilane by Carbon Tetrachloride Solution Casting

2002 ◽  
Vol 17 (1) ◽  
pp. 214-223 ◽  
Author(s):  
Masaki Narisawa ◽  
Takeshi Hasegawa ◽  
Kiyohito Okamura ◽  
Masayoshi Itoh ◽  
Thomas Apple ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Carbon Tetrachloride ◽  
Radical Polymerization ◽  
Air Flow ◽  
Spectroscopic Studies ◽  
Flow Time ◽  
Silica Layer ◽  
Solution Casting ◽  
Amorphous Films ◽  
Carbon Tetrachloride Solution

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.

scholarly journals Mechanistic Investigations of an α-Aminoarylation Photoredox Reaction

2021 ◽  
Author(s):  
Bernard Stevenson ◽  
Ethan Spielvogel ◽  
Emily Loiaconi ◽  
Victor M. Wambua ◽  
Roman Nakhamiyayev ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Absorption Spectroscopy ◽  
Rate Constant ◽  
Kinetic Modeling ◽  
Rate Constants ◽  
Transient Absorption ◽  
Coupling Reaction ◽  
Time Dependent ◽  
Transient Absorption Spectroscopy ◽  
Mechanistic Investigations

We present time-dependent percent and quantum yield measurements of a photoredox-catalyzed coupling reaction between 1,4-dicyanobenzene and N-phenylpyrrolidine. We also use transient absorption spectroscopy to examine the kinetics within the reaction and use kinetic modeling to extract rate constants and predict how changes in rate constant will impact the quantum yield.

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