Detailing the Structure of Liquid THF Based on an EPSR Study

Abstract

The structure of pure liquid tetrahydrofuran (THF) has been investigated via Monte Carlo simulations in the wake of a previous Empirical Potential Structure Refinement (EPSR) study on that liquid (Bowron, D.T.; Finney, J.L.; Soper, A.K. (2006) J. Am. Chem. Soc., 128, 5119). The molecules are all-atoms rigid structures and the intermolecular potential used is described for the classical 6-12 Lennard-Jones plus Coulomb in the NPT ensemble at 1 atm and 25˚C. THF is a poorly structured liquid. Typical preferred orientation of molecules has been explored and calculations shown different types of molecular pairs exist concurrently in the liquid. The geometry of those pairs was deeply investigated and its influence in the liquid structure discussed. The lack of molecular organization in the liquid is closely related to the existence of that diversity of molecular pairs. Its geometry changes from antiparallel up to T-like depending on the distance between the molecules in the pairs.