Estimation of the molar heat capacity change on melting of organic compounds

A simple equation to predict the differential molar heat capacity (ΔCp _m) of the solid and liquid forms for the organic compounds at their melting point (T _m) is developed. Only three parameters are used: the molecular flexibility number (τ), the molecular symmetry number (σ), and the hydrogen bond number (HBN). The results for more than 100 compounds show that the average absolute error of ΔCp _m is 13.4 J/(mol K). This is less than the average absolute errors obtained by any of the three schemes proposed in a previous report [Pappa, G. D.; Voutsas, E. C.; Magoulas, K.; Tassios, D. P. Ind. Eng. Chem. Res. 2005, 44, 3799].