Reactions of thiyl radicals. V. The gas phase photolysis of methyl disulfide and ethyl disulfide mixtures in the presence of ethylene

1968 ◽  
Vol 46 (14) ◽  
pp. 2462-2464 ◽  
Author(s):  
P. M. Rao ◽  
A. R. Knight
Keyword(s):  
Gas Phase ◽  
Methyl Ethyl ◽  
Thiyl Radicals ◽  
Disulfide Formation ◽  
Presence And Absence ◽  
Low Efficiency

The gas phase photolysis of methyl disulfide and ethyl disulfide and their mixtures, in the presence and absence of ethylene, has been studied at 25 °C and λ = 2300–2800 Å. The pure substrates give predominantly the corresponding thiol, whereas co-photolysis yields methyl ethyl disulfide in appreciably larger yields.When ethylene is added, the substrates individually show a reduction in RSH rate and the formation of relatively small amounts of sulfides. In their co-photolysis, added C2H4 does not appreciably alter the rate of methyl ethyl disulfide formation, indicating a low efficiency of RS scavenging by the olefin in this system.Isopropanol and 2,3-dimethyl butane do not increase the thiol yield from the pure substrates.

scholarly journals Reactions of thiyl radicals. III. Photochemical equilibrium in the photolysis of liquid disulfide mixtures

1968 ◽  
Vol 46 (6) ◽  
pp. 999-1003 ◽  
Author(s):  
K. Sayamol ◽  
A. R. Knight
Keyword(s):  
Room Temperature ◽  
High Efficiency ◽  
Incident Radiation ◽  
Thiyl Radical ◽  
Methyl Ethyl ◽  
Disulfide Linkage ◽  
Thiyl Radicals ◽  
Disulfide Formation ◽  
Photostationary State ◽  
State Concentration

The photolysis of mixtures of liquid methyl disulfide and ethyl disulfide at room temperature at wavelengths greater than 2300 Å has been investigated. The sole detectable product is methyl ethyl disulfide which reaches a photostationary state concentration after relatively short irradiation periods. For various initial mixtures, the concentration of the three disulfides in the photostationary state can be correlated in terms of an equilibrium constant, K = [RSSR′]/[RSSR]1/2[R′SSR′]1/2, whose value is 2.05 ± 0.04. The quantum yield of unsymmetrical disulfide formation in the initial stages of the reaction is 330 for an absorbed intensity of 4.70 × 10−2 μeinstein/min when the incident radiation is confined to λ = 2600 + 50 Å. The exceptionally high efficiency of the overall process is ascribed to the chain-propagating step[Formula: see text]which likely proceeds through attack of the thiyl radical on the S—S disulfide linkage.

Hydrogen bonding in the gas phase: the thermodynamic properties of hydrogen fluoride-ether complexes and their far infrared spectra

1971 ◽  
Vol 322 (1548) ◽  
pp. 137-146 ◽  
Keyword(s):  
Hydrogen Bonding ◽  
Gas Phase ◽  
Infrared Spectra ◽  
Equilibrium Constants ◽  
Far Infrared ◽  
Methyl Ethyl ◽  
Rotational Contour ◽  
Stretching Vibration ◽  
Conformational Rearrangements ◽  
Far Infrared Spectra

The equilibrium constants of gas-phase complexes of HF with dimethyl, methyl ethyl and diethyl ether have been measured at several temperatures using the Benesi-Hildebrand approximation on the absorption band of the HF stretching vibration in the complex. From these, values of Δ H of — 43, — 38 and — 30 kJ mol -1 respectively, have been determined. They are interpreted in terms of conformational rearrangements of the ethers when they form hydrogen bonds. The far infrared spectra of the complexes with both HF and DF have also been recorded and in each case a band observed at around 180 cm -1 which is assigned to the intermolecular stretching mode of vibration. For the complex between HF and dimethyl ether a rotational contour has been observed at about 10 cm -1 .

A Study of the Pyrolysis of Methyl Ethyl and Diethyl Carbonates in the Gas Phase

1965 ◽  
Vol 69 (9) ◽  
pp. 3013-3017 ◽  
Author(s):  
Alvin S. Gordon ◽  
William P. Norris
Keyword(s):  
Gas Phase ◽  
Methyl Ethyl

scholarly journals Pressure dependent aerosol formation from the cyclohexene gas-phase ozonolysis in the presence and absence of sulfur dioxide: a new perspective on the stabilisation of the initial clusters

2012 ◽  
Vol 14 (33) ◽  
pp. 11695 ◽  
Author(s):  
Philip Thomas Michael Carlsson ◽  
Janina Elisabeth Dege ◽  
Claudia Keunecke ◽  
Bastian Christopher Krüger ◽  
Jan Lennard Wolf ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Gas Phase ◽  
Aerosol Formation ◽  
Presence And Absence ◽  
New Perspective

Rate of14N2 desorption from the surfaces of nitrides in the presence and absence of15N2 in the gas phase

1985 ◽  
Vol 29 (2) ◽  
pp. 433-441 ◽  
Author(s):  
V. I. Sobolev ◽  
G. I. Panov ◽  
A. S. Kharitonov
Keyword(s):  
Gas Phase ◽  
Presence And Absence
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