Heats of formation of organic molecules calculated from ab initio theory and a group equivalent scheme: Alkenes

A bond and group equivalent scheme that allows the calculation of heats of formation of alkenes from ab initio 6-31G* energies has been developed. For a group of 26 compounds, the root mean square (rms) error for the calculated heat of formation was 0.78 kcal/mol. Heats of formation have been predicted for an additional nine compounds for which the experimental values are either unknown or suspect. The heats of hydrogenation of barrelene and related compounds are discussed. © 1994 by John Wiley & Sons, Inc.