Estimation of thermodynamic properties of organic compounds using fragment-based and topological descriptors

A system of molecular descriptors is proposed for finding structure-property relationships and calculating the boiling points, the heats of vaporization, and vapor pressures. This system combines the fragment-based and topological description of molecular structures. The correlation equation made it possible to estimate the thermodynamic properties of saturated hydrocarbons with high accuracy. Boiling points of 198 compounds, including alkane isomers containing up to ten carbon atoms and cyclic hydrocarbons, is calculated with a root-mean-square deviation sigma from the experiment equal to 3.4 K (the correlation coefficient is r = 0.9966). The heats of vaporization for 66 saturated hydrocarbons are estimated with sigma = 0.942 kcal/mol (r = 0.9939). The saturated vapor pressures under normal conditions for 73 saturated hydrocarbons are estimated with sigma = 0.0728 logarithmic units (r = 0.9961).