Dicyclohexanecarbonylsulphate: a precursor of cyclohexyloxocarbenium ions

1977 ◽  
Vol 55 (2) ◽  
pp. 355-359 ◽  
Author(s):  
E. Montoneri ◽  
L. Giuffré ◽  
M. Cassago ◽  
E. Tempesti ◽  
M. Fornaroli
Keyword(s):  
Low Temperature ◽  
Sulphur Dioxide ◽  
Liquid Sulphur ◽  
Sulphur Trioxide ◽  
Equimolar Solution

Dicyclohexanecarbonyl sulphate (1) is the prevailing species in the equimolar solution of cyclohexanecarboxylic anhydride and sulphur trioxide in liquid sulphur dioxide. The ionization of 1 to cyclohexyloxocarbenium ions occurs only in the presence of excess sulphur trioxide. Both 1 and C6H11CO+ are stable only in solution and at low temperature.

THE RAMAN SPECTRA OF LIQUID SULPHUR TRIOXIDE AND SOLUTIONS OF SULPHUR TRIOXIDE IN INERT SOLVENTS

1961 ◽  
Vol 39 (11) ◽  
pp. 2189-2200 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Carbon Tetrachloride ◽  
Raman Spectra ◽  
Sulphur Dioxide ◽  
Monomeric Form ◽  
Polymeric Form ◽  
Cyclic Trimer ◽  
Low Concentrations ◽  
Polymeric Species ◽  
Liquid Sulphur ◽  
Sulphur Trioxide

The Raman spectra of liquid sulphur trioxide and of sulphur trioxide dissolved in a number of "inert" solvents have been investigated. A detailed analysis of the spectrum of liquid sulphur trioxide supports the earlier suggestion of Gerding and Nijveld that the main polymeric species in liquid sulphur trioxide is the cyclic trimer. Frequencies are assigned for all the Raman active vibrations of the cyclic trimer. These assignments differ substantially from those given previously by Gerding and Nijveld.The spectra of dilute solutions of sulphur trioxide in sulphur dioxide, sulphuryl chloride, carbon tetrachloride, tetrachlorethylene, and trichlorfluormethane (Freon 11) show that the sulphur trioxide is present mainly in the monomeric form at low concentrations while at higher concentrations a polymeric form, which is very probably the trimer, is also present.

New Observations on the Low Temperature Reaction between Hydrogen Sulphide and Sulphur Dioxide : A Novel Method for Analysing Milligram Quantities of Hydrogen Sulphide in the Presence of Carbon Dioxide

1959 ◽  
Vol 12 (3) ◽  
pp. 424 ◽  
Author(s):  
IK Gregor ◽  
RL Martin
Keyword(s):  
Carbon Dioxide ◽  
Low Temperature ◽  
Hydrogen Sulphide ◽  
Sulphur Dioxide ◽  
High Vacuum ◽  
Temperature Reaction ◽  
Liquid Sulphur ◽  
Vacuum Method ◽  
Novel Method ◽  
Vacuum Fractionation

When an anhydrous mixture of liquid hydrogen sulphide and liquid sulphur dioxide contained in a sealed tube at -78 �C is gently warmed, the liquid remains clear until the temperature reaches c. -40 �C, when sulphur is slowly deposited. Careful measurements reveal that the two compounds always react in the mole ratio, H2S : SO2 = 3 : 2, which contrasts with the stoichiometric equation 2H2S + SO2 =2H2O + 3S, widely quoted for their reaction in the moist gaseous phase or in aqueous solution. This low temperature reaction forms the basis of a novel high vacuum method for estimating milligram quantities of hydrogen sulphide when in the presence of gases, such as carbon dioxide, whose volatilities are sufficiently similar to preclude the use of normal low-temperature vacuum fractionation methods.

The absorption spectrum of SO and the flash photolysis of sulphur dioxide and sulphur trioxide

1959 ◽  
Vol 249 (1259) ◽  
pp. 498-512 ◽  
Keyword(s):  
Absorption Spectrum ◽  
Dissociation Energy ◽  
Sulphur Dioxide ◽  
Flash Photolysis ◽  
Ultra Violet ◽  
Vibrationally Excited ◽  
A Value ◽  
Continuous Absorption ◽  
Sulphur Trioxide ◽  
Normal Spectrum

The flash photolysis of sulphur dioxide under adiabatic conditions results in the complete temporary disappearance of its spectrum , which then slowly regains its original intensity over a period of several milliseconds. Simultaneously with the disappearance of the sulphur dioxide spectrum a continuous absorption appears in the far ultra-violet and fades slowly as the sulphur dioxide reappears. It is shown that the effect of the flash is thermal rather than photochemical, and the possibility of the existence of an isomer of sulphur dioxide at high temperatures is discussed; the disappearance of the normal spectrum on flashing is explained in this way. Several previously unrecorded bands of SO observed in the photolysis indicate that the vibrational numbering of its spectrum should be revised by the addition of 2 to the present values of v' . This leads to a value of the dissociation energy of 123.5 kcal. In formation about the levels v' = 4, 5 and 6 has also been obtained. The isothermal flash photolysis of sulphur trioxide results in the appearance of vibrationally excited SO, and the primary photochemical step in this reaction is discussed.

scholarly journals Reaction Mechanism of Formation of CaSO4 in AFBC

1970 ◽  
Vol 41 (3) ◽  
pp. 167-170
Author(s):  
Ismat Ali ◽  
M Mohsin Ali
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Content ◽  
Fluidized Bed ◽  
Sulphur Dioxide ◽  
Calcium Sulphate ◽  
Mechanism Of Formation ◽  
Sulphur Trioxide ◽  
Fluidized Bed Combustor

Attempts have been made to investigate and predict the reaction mechanism of formation of calcium sulphate (CaSO4) in Atmospheric Fluidized Bed Combustor (AFBC). Formation of NOx, from nitrogen content to coal has been found beneficial for the oxidation of sulphur dioxide to sulphur trioxide. Bangladesh J. Sci. Ind. Res. 41(3-4), 167-170, 2006

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