Aliphatic nitroalkanes: Evaluation of thermochemical data with complementary experimental and computational methods

Abstract

Thermochemical properties of aliphatic nitroalkanes available in the literature are scarce and inconsistent. New standard molar enthalpies of vaporization and sublimation of 2-nitropropane, 2-methyl-2-nitropropane, and 2,3-dimethyl-2,3-dinitrobutane were derived from the vapor pressure temperature dependence measured by the transpiration method. Thermodynamic data on linear and branched aliphatic mono- and di-nitroalkanes available in the literature were combined with own experimental results and evaluated with help of empirical and theoretical methods aiming at recommendation of the sets of vaporization and formation enthalpies for aliphatic nitroalkanes as the reliable benchmark properties for further thermochemical calculations. Gas phase standard molar enthalpies of formation of aliphatic nitro-compounds derived by high-level quantum-chemical method G4 were found in a good agreement with the evaluated and recommended experimental data. Group-additivity procedure for calculation of vaporization and formation enthalpies have been developed and tested.