Prediction of Standard Enthalpies of Formation

Abstract

A number of methods for relating the standard enthalpy of formation of a compound in its ideal-gaseous state to its molecular structure are considered in detail by Cox and Pilcher [70COX/PIL]. The most generally applicable parametric schemes are the ‘Benson’, ‘Laidler’ and ‘Allen’ procedures; Cox and Pilcher show that these three methods are mathematically equivalent. However some important steric interactions between non-bonded atoms and conjugative effects between formally localized bonds are not explicitly allowed for in the values for the parameters. They are thus often difficult to estimate to kJ mol⁻¹ accuracy.