THE THERMODYNAMICS OF PROTONATION OF SOME SULPHIDE CONTAINING DIAMINES IN AQUEOUS SOLUTION

Abstract
The protonation properties of 1,7-diaza-4-thiaheptane, 1,8-diaza-4-thiaoctane, 1,9-diaza-4-thianonane and 1,9-diaza-5-thianonane have been investigated potentiometrically and calorimetrically at 25°C in 0.5 mol dm−3 (K)NO3 solution. Values for the protonation constants and for the thermodynamic functions δH° and δS° were determined. The results have been discussed. It has been found that the place of the thioether group in the aliphatic chain, connecting the two aminogroups, predominantly determines the behaviour of the diamines when protonated.