Spectroscopic Properties of Sulphoxides

The methylene protons in dibenzyl sulphoxide are magnetically equivalent in solvents of low dielectric constant, but non-equivalent in polar solvents. This behaviour is reversed for diphenacyl sulphoxide the non-equivalence arises, on changing solvent, from the downfield shift of one of the methylene protons with increasing polarity. Solvent effects on the deuteriation of 

Cinquini, S. Colonna, I. Moretti, and G. Torre, Tetrahedron Letters, 1970, 2773. 

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