Review Article
Lawrence S. Bartell
Abstract
Nearly a half-century ago I published a paper which successfully calculated the relative stabilities of a large number of hydrocarbons. Calculations were based on empirical atom-atom potential energies I had introduced in 1960, which had been deliberately biased to take into account the differences between branched and u n b r a n c h e d hydrocarbon molecules. Little controversy arose until quite recently when Gronert revived this old work and entered into what evolved into a bitter controversy with the Grimme, Wiberg, and Schleyer accounts of stabilities of branched vs. unbranched hydrocarbons. Gronert invoked 1-3 nonbonded interactions to reproduce successfully the relative stabilities of the various hydrocarbons. His opponents carried out careful quantum computations including electron correlation energies (not feasible to calculate in 1960 when the empirical interaction potentials were formulated). The purpose of this paper is to resolve the controversy by showing that while the two approaches differ in verbal explanations; they are equivalent in concrete results.