Estimating pure component vapor pressures of complex organic molecules

Modifications of the entropy of boiling term and heat capacity change upon boiling term are made to the Yalkowsky - Mishra vapor pressure equation. These modifications eliminate a systematic error and enable the pure component vapor pressure estimation of complex organic compounds, including those that are hydrogen bonding. The new vapor pressure equation, which requires only the knowledge of transition temperatures and molecular structure, is shown to be more accurate than the Yalkowky - Mishra equation for a wide variety of compounds over a wide range of temperatures (vapor pressures from 1 atm and below).