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.

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.

Application of Raman Spectroscopy to the Study of Adsorption Effects at Liquid-Solid Interfaces

1982 ◽  
Vol 36 (4) ◽  
pp. 471-473 ◽  
Author(s):  
Klaus Witke
Keyword(s):  
Raman Spectroscopy ◽  
Carbon Tetrachloride ◽  
Adsorption Isotherm ◽  
Minimal Surface ◽  
Linear Relationship ◽  
Surface Area ◽  
Long Range ◽  
Raman Spectra ◽  
Sample Cell ◽  
Minimal Surface Area

A sample cell for investigating suspensions or emulsions by Raman spectroscopy in the optically favorable 90° scattering arrangement is described. The Raman spectra of pyridine in a suspension of Aerosil 200 in carbon tetrachloride are recorded. The adsorption isotherm of pyridine is determined from the intensities of the Raman lines at 1008 and 990 cm−1. Over a long range of coverage a linear relationship exists between reciprocal concentrations of chemisorbed and dissolved molecules. The minimal surface area that is occupied by a chemisorbed molecule is determined to be approximately 0.75 nm2.

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.

RAMAN SPECTRA OF THE H2SO4–SO3 AND D2SO4–SO3 SYSTEMS: EVIDENCE FOR THE OCCURRENCE OF POLYSULPHURIC ACIDS

1962 ◽  
Vol 40 (4) ◽  
pp. 658-674 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson
Keyword(s):  
Sulphuric Acid ◽  
Raman Spectra ◽  
Ionic Species ◽  
The Self ◽  
Experimental Results ◽  
Similar Work ◽  
Stretching Vibrations ◽  
Sulphur Trioxide ◽  
High Concentrations

The Raman spectra of oleums, i.e. mixtures of sulphur trioxide and sulphuric acid, have been re-examined. Similar measurements on the sulphur trioxide – deuterosulphuric acid (D2SO4) system are also reported. The experimental results and conclusions of previous similar work on oleums are discussed. By comparison of the spectra of oleums with those of the polysulphuryl halides it is shown that the polysulphuric acids H2S2O7 and H2S3O10 are present in this system. The increase in the frequency of the SO2 stretching vibrations with increasing concentration of sulphur trioxide gives evidence for the existence of higher polysulphuric acids such as H2S4O13 at high concentrations of sulphur trioxide. In relatively concentrated oleum, sulphur trioxide monomer and trimer are also present. It is shown that the self-dissociation of liquid H2S2O7 gives mainly molecular H2S2O10 and H2SO4 and not ionic species. The conclusions reached from the interpretation of the Raman spectra of the D2SO4–SO3 system are similar to those arrived at for sulphuric acid oleums. The spectra of solutions of NaHSO4 in oleums were also examined, and are discussed.

Soluble Fibrin in Plasma at 37°C Exists as DES-A Fibrin in Monomeric Form

1979 ◽  
Author(s):  
G. Müller-Berghaus ◽  
I. Mahn ◽  
W. Krell ◽  
I. Kröhnke
Keyword(s):  
Complex Formation ◽  
Human Plasma ◽  
Gel Filtration ◽  
Monomeric Form ◽  
Polymeric Form ◽  
Soluble Fibrin

We intended to find out in which state fibrin exists in plasma at 37°C. In order to generate fibrin, small amounts of thrombin were added to human plasma containing 125I-fibrinogen, Thereafter, thrombin was quenched with hirudin and “31I-fibrinogen added to observe possible 125I-fibrin-131I-fibrinogen complex formation. Gel filtration of this mixture on sepharose columns equilibrated with plasma revealed 2 peaks. At 20°C, but not at 37°C, peak A eluted in front of the fibrinogen peak contained fibrin-fibrinogen complexes. If isolated fractions of peak A eluted at 20°C were rechromatographed at 37°C, the material was mainly eluted in peak B (= fibrinogen peak). If isolated fractions of peak B eluted at 37°C were rechromatographed at 20°C, part of the 125I-radioactivity representing fibrin was eluted in peak A. As purified des-AB fibrin is eluted in polymeric form at 37°C and as purified des-A fibrin is eluted only in monomeric form at 37°C, we conclude from our experiments that fibrin genera, ting in plasma at 37°C exists in monomeric form. Furthermore, the experiments demonstrate that des-A fibrin does not form complexes with fibrinogen or other proteins at 37°C (Supported by the DFG).

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