Optimized intermolecular potential functions for liquid alcohols

Intermolecular potential functions have been developed for use in computer simulations of liquid alcohols and other molecules with hydroxyl groups. The functions are based on earlier work for liquid hydrocarbons and required introduction of few new parameters. Optimization of the parameters involved studids of hydrogen-bonded complexes and Monte Carlo simulations for liquid methanol. Further application then consisted of Monte Carlo simulations for liquid methanol, ethanol, 1-propanol, 2-propanol, and 2-methyl-2-propanol at 25 O C and 1 atm. Extensive thermodynamic and structural results are reported for the liquid alcohols and are compared with experimental data. The excellent accord between simulation and experiment is remarkable in view of the simple form and facile parametrization of the potential functions. The five liquid alcohols all feature winding hydrogen-bonded chains with averages of close to two hydrogen bonds per molecule. The hydrogen bonding is also found to have interesting effects on the torsional energy surfaces for molecules in the liquids. Most striking is a narrowing of the conformational energy wells for rotation about the C-0 bonds.