Group Contribution Revisited: The Enthalpy of Formation of Organic Compounds with “Chemical Accuracy”

Abstract

We established a group contribution (GC) parametrization for the heat of formation of organic molecules, but, and this is new, revealed chemical accuracy (1 kcal/mol). Compared to previous approaches which did not achieve this result, we succeeded by (i) taking reliable and consistent experimental data, (ii) not relying on computer-assisted automated parameter estimation, (iii) taking into account the physico-chemistry known for years, i.e., only introducing additional parameters when we understand the physico-chemistry, and finally, (iv) acknowledging that the linear additive GC method has its limits and cannot account properly for any molecule. Not only the averaged absolute deviations but also the individual results were almost without exception within chemical accuracy, except for some more heavily substituted molecules for which the group contribution approach breaks down.

Keywords

• enthalpy of formation
• thermodynamics
• process design
• physico-chemical property prediction
• group-contribution method
• chemical accuracy