ESTIMATING ENTROPIES AND ENTHALPIES OF FUSION OF ORGANIC-COMPOUNDS

A group additivity method recently reported for estimating fusion entropies and fusion enthalpies of hydrocarbons is expanded to include both mono- and multisubstituted derivatives as well. The parameters are derived from experimental fusion enthalpies of 191 hydrocarbons and 225 monosubstituted and 233 multisubstituted hydrocarbon derivatives. Group values are provided for many structural environments. Applications of the technique are described. The average deviation between experimental and calculated fusion entropies and enthalpies obtained for monosubstituted derivatives is +/- 1.77 eu and +/- 0.49 kcal/mol, respectively. This increases to +/- 2.0 eu and +/- 0.76 kcal/mol, respectively, for multisubstituted derivatives and can be compared with values of +/- 1.85 eu and +/- 0.56 kcal/mol previously reported for hydrocarbons.