A norm indexes-based QSPR model for predicting the standard vaporization enthalpy and formation enthalpy of organic compounds

Abstract

As important thermodynamic properties, vaporization enthalpy and formation enthalpy were extensively utilized in the chemical industry process and chemical engineering design, environment and agriculture. Based on the concept of norm index proposed by our group previously, a unified QSPR model was built for predicting four properties endpoints for 14 families of organic compounds. Four thermodynamic properties endpoints, including standard vaporization enthalpy (ΔHv0), standard formation enthalpy in gas state (ΔHf0(g)), standard formation enthalpy in solid state (ΔHf0(s)) and standard formation enthalpy in liquid state (ΔHf0(l)), were involved in the same modelling work. This model has satisfactory fitting effect for four properties endpoints with R2 of 0.967 for ΔHv0, R2 of 0.990 for ΔHf0(g), R2 of 0.989 for ΔHf0(s) and R2 of 0.987 for ΔHf0(l), respectively. Moreover, the results of internal validation, external validation and applicability domain analysis indicated the good stability and robustness of this model. This work not only calculated vaporization enthalpy and formation enthalpy with the same formula, but also covered gas, solid and liquid phases for formation enthalpy. Satisfying results obtained in the present work suggest that this model and norm indexes have good reliability and generalization.