Hydrates of Organic Compounds. XVI. Determination of the Melting Points and Hydration Numbers of the Hydrates of Tetrabutyl(or Tetraisopentyl)ammonium Alkanesulfonates

Article abstract of DOI:10.1246/bcsj.64.3023

The solid liquid phase diagrams of binary mixtures of water with tetraisopentylammonium alkanesulfonates, <(i-C5H11)4N> (n=1-8), bis(tetrabutylammonium) alkanedisulfonates, <(n-C4H9)4N>2 (n=2-5), and with bis(tetraisopentylammonium) alkanedisulfonates, <(i-C5H11)4N>2 (n=2-5), were examined in order to confirm the formation of hydrates.For all of the sulfonates examined the formation of hydrates has been newly confirmed.The hydrates of the tetraisopentylammonium alkanesulfonates have hydration numbers of around 37-40 and fairly high melting points (lie between 13 and 19 deg C).The typical hydrates formed by the bis(tetrabutylammonium) alkanedisulfonates have hydration numbers of around 52 and those by the bis(tetraisopentylammonium) alkanedisulfonates around 76.The former disulfonate hydrates have low melting points (between 1.0 and 10 deg C).However, the latter disulfonate hydrates have fairly high melting points (between 13 and 18 deg C).A salt with n=4 forms the most stable hydrate for both series of alkanedisulfonates.Judging from the hydration numbers and melting points, these hydrates seem to be clathrate-like.