Hydrates of Organic Compounds. X. The Formation of Clathrate Hydrates of Tetrabutylammonium Alkanesulfonates

Abstract

Abstract The solid–liquid phase diagrams of binary mixtures of water with tetrabutylammonium alkanesulfonate (n-C4H9)4NO3SR(R=CH3–C5H11) and with tetrabutylammonium benzenesulfonate were examined in order to confirm the formation of clathrate-like hydrates. It has been found that (1) all the sulfonates examined can form clathrate-like hydrates with hydration numbers either around 30 or around 39; (2) these hydrates can be classified into three groups I, II, and III on the basis of the hydration numbers and melting points just as in the case of a series of tetrabutylammonium carboxylate hydrates; and (3) generally, the melting points of these sulfonate hydrates are lower than those of tetrabutylammonium carboxylate hydrates. The formation of clathrate-like hydrates of tetrabutylammonium hydrogensulfite and of tetrabutylammonium sulfite has also been reported and is discussed in an appendix.