UBC Theses and Dissertations
Interactions of sulphur dioxide with polar molecules De Maine, Paul Alexander Desmond
Analysis of the sulfur dioxide long wavelength band, appearing in n-ROH or benzene and carbontetrachloride solutions, has been obtained in terms of the system:- donor + SO₂ ⇌ complex The characteristic constants for the MeOH , EtOH , n-PrOH, n-BuOH and benzene complexes and the heat of formation of the benzene and ethanol complexes with sulfur dioxide in carbontetrachloride have been estimated. Structures for the n-ROR – SO₂ complexes have been proposed along the lines of Mulliken's simple charge transfer theory. It has been shown that the spectroscopic behaviour of sulfur dioxide in mixed benzene - ethanol solutions is adequately explained in terms of the binary donor system:- benzene + SO₂ ⇌ (complex)₁ ethanol + SO₂ ⇌ (complex)₂ if it is assumed that the characteristic constants for both complexes and the molar extinction curve of free sulfur dioxide remains unchanged in passing from non - polar to polar solvents. From a similar analysis of the new band appearing in hydroquinone - sulfur dioxide - ethanol solutions, the characteristic constants and heat of formation of the hydroquinone - sulfur dioxide complex have been obtained. The value for the heat of formation of this complex is in good agreement with the reported value of the heat of decomposition of the hydroquinone - sulfur dioxide clathrate compound. This fact, together with the evidence of the binary donor character of the ethanol - benzene - sulfur dioxide system is strong evidence in favour of the proposed theory of the formation of liquid lattice penetration complexes (by penetration of the liquid lattice by sulfur dioxide). From studies of the temperature dependence of the long wavelength band in sulfur dioxide - water solutions, it has been concluded that neither Ley and Konig nor Boyd Campbell and Maass’ theories adequately describe the behaviour of the sulfur dioxide - water system. A new theory has been proposed which qualitively describes the behaviour of this system. However, attempts to obtain values for the constants involved from the absorption spectra of water-ethanol-sulfur dioxide solutions, have been unsuccessful. This has been attributed to the simultaneous formation of ethanol - water interpenetration complexes (water penetrating the ethanol lattice).
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