Benchmark thermodynamic properties of alkanediamines: Experimental and theoretical study

Highlights: • Vapor pressures of 1,2-propanediamine and 2-methyl-1,2-propanediamine were measured. • Vaporization enthalpies were derived and compared with the literature. • Thermochemical data were tested for consistency using additivity rules and computations. • Thermodynamic functions of 1,2-alkanediamines were calculated. • Simple method to assess gas phase entropies based on the G3MP2 method is suggested. - Abstract: Vapor pressures of (dl)-1,2-propanediamine and 2-methyl-1,2-propanediamine were measured using the transpiration method. Molar enthalpies of vaporization were derived from the vapor pressure temperature dependence. Thermodynamic data on alkanediamines available in the literature were collected and treated uniformly. Consistency of the experimental data set for alkanediamines was evaluated with group-contribution and quantum-chemical methods. The standard molar entropy of formation and the standard molar Gibbs function of formation have been calculated. Vaporization and formation enthalpies of alkanediamines of benchmark quality are recommended for practical thermochemical calculations and validation of empirical and theoretical methods