Multiorientation Model for Planar Ordering of Trimesic Acid Molecules

Abstract

We present a study of the q-orientational statistical model for the self-assembly of symmetric triangular molecules of trimesic acid in two dimensions. Density functional theory is used to estimate the pair interactions of two such molecules located at the ground state (dimeric H-bond) distance for q2 different mutual orientations of these molecules. The interaction energies for models with q up to 120 are determined. The Monte Carlo simulation employing these interactions reveals the ordering of the molecules into the honeycomb (HON) phase for the entire range of models (q = 2–120) which is manifested by the peak in temperature dependence of the specific heat CV(T). The increase of q from 2 to 120 causes the ordering temperature Tc to decrease and become much closer to the experimental value. Our results imply that in terms of computational efficiency and the magnitude of Tc, the q = 12 model is the optimal choice for calculations. The CV(T) dependence has a second peak at a low temperature point T1 < Tc...