Theoretical studies of the Wilcox molecular torsion balance. Is the edge-to-face aromatic interaction important?

[formula: see text] Molecular mechanics calculations with several different force fields and the GB/SA solvation model were carried out for the molecular torsion balance developed by Wilcox et al. to investigate the intramolecular nonbonded interactions between two aromatic rings. The preference is found to arise from a balance between intramolecular van der Waals interactions and solvation effects, with the latter favoring the unfolded conformation.