Calculation of the Thermodynamic Properties of Polycyclic Aromatic Hydrocarbons by and Incremental Procedure

摘要

Uniform substances are characterized by both their thermo-dynamic and their molecular properties. After the triumphs of quantum chemistry, it has been possible in the past decade to calculate the inherent molecular properties of compounds in the gas phase. Certain thermodynamic properties of substances, like the melting and boiling point, the vapor pressure, and the corresponding energy values of the phase transitions, are ensemble properties of molecules and thus not accessible with these methods. Apart from group theoretical procedures, several empirical methods are used for the prediction of theses properties. The vapor pressure and the enthapy of sublimation of synthetic compounds (xenobiotics) are important properties relevant for the environment, and a relationship between structure and these thermodynamic quantities can be used in model calculations for otherwise unknown values.