jp068560t_si_001.pdf (159.3 kB)
Properties and Structure of Aromatic Ester Solvents
journal contribution
posted on 2007-05-03, 00:00 authored by Santiago Aparicio, Rafael Alcalde, María J. Dávila, Begoña García, José M. LealThis paper reports on an experimental and theoretical study of the aromatic ester solvents family. Several
compounds were selected to analyze the different factors that influence their liquid-state properties and
structures. The pressure−volume−temperature behavior of these fluids was measured accurately over wide
temperature and pressure ranges and correlated successfully with the empirical TRIDEN equation. From the
measured data the relevant derived coefficients of isothermal compressibility, isobaric expansibility, and internal
pressure were calculated. The statistical associating fluid theory (SAFT) and perturbed chain statistical
associating fluid theory (PC-SAFT) molecularly based equations of state were used to predict the PVT behavior
with model parameters obtained from the correlation of available saturation literature data; the results provided
by PC-SAFT equations of state were clearly superior for all of the studied solvents. The fluid's molecular
level structure was studied by quantum computations at the B3LYP/6-311++g** level and classical molecular
dynamics simulations in the NPT ensemble with the OPLS-AA forcefield. Molecular parameters, such as
torsional barriers or cluster energetics, were analyzed as a function of ester structures. The molecular dynamics
study provides, on one hand, theoretical values of thermophysical properties, which are compared with the
experimental ones, and, on the other hand, valuable molecular level structural information. On the basis of
both macroscopic and microscopic studies complex fluid structures were inferred with important effects arising
from the geometries of the studied molecules and from the existence of remarkable intermolecular forces of
dominating dipolar nature.