Vaporization enthalpies of benzanthrone, 1-nitropyrene, and 4-methoxy-1-naphthonitrile: Prediction and experiment

Abstract

Determination of the vaporization enthalpies of low-volatile organic compounds in the wide temperature range is a non-trivial experimental task. A number of predictive approaches were proposed to resolve this problem. Independent validation is necessary for the further development. In this work the saturated vapor pressures of 3 substituted polyaromatic compounds, 1-nitropyrene, benzanthrone, and 4-methoxy-1-naphthonitrile, were measured between 375 and 480 K using fast scanning calorimetry. From the measured vapor pressure – temperature dependences the vaporization enthalpies were derived. The experimental vaporization enthalpies were compared to the literature data and empirical approaches. The vaporization enthalpies of the studied compounds were calculated at 298.15 K from the molecular structure and then adjusted to the measurement temperatures, following two different schemes. The first is based on the approach employing a correlation between the difference of ideal gas phase and liquid heat capacities, on the one hand, and the vaporization enthalpy at 298.15 K, on the other hand, recently proposed by our group. The second is widely known Chickos et al. scheme. Consistence of the experimental, literature, and predicted data was critically analyzed.