Estimation of heat capacity of boiling of organic compounds

The aim of this study is to develop a widely applicable model for predicting the heat-capacity change associated with boiling at atmospheric pressure (Delta C-pb) of organic compounds. A semiempirical model is generated utilizing a flexibility index (tau) and a hydrogen-bonding parameter. This model is based upon experimental apparent Delta C-pb values of 619 organic compounds. The average absolute error for the estimation is 7.1 J/K mol. The proposed model quantitatively establishes the impact of flexibility and hydrogen bonding on the apparent Delta C-pb. It is shown to be more accurate when compared to some of the previously described methods.