Vapor pressure and enthalpy of vaporization of linear aliphatic alkanediamines

Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkanediamines H2N–(CH2)n–NH2 with n = (3 to 12) have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the alkanediamines with the number n and with the Kovat’s indices has been found, proving the internal consistency of the measured data.

► We measured vapor pressure of diamines H2N–(CH2)n–NH2 with n = 3 to 12. ► Vaporization enthalpies at 298 K were derived. ► We examined consistency of new and available in the literature data. ► Enthalpies of vaporization show linear dependence on numbers n. ► Enthalpies of vaporization correlate linearly with Kovat’s indices.