Revisiting the origin of the preferential π-π stacking conformation of the (+)-8-phenylmenthyl acrylate

Abstract

In this paper we report a theoretical study aiming to revisit the origin of the preferential π-π stacking conformation of the (+)-8-phenylmentyl acrylate (2). For this, we have applied several DFT and ab initio methods to calculate local minimum geometries, vibrational frequencies, thermochemical properties and ¹H NMR chemical shifts for 2 and the model compound 3-phenylpropyl acrylate (3). We have observed that the MPW1B95 functional was the most suitable method to explain ¹H NMR experimental data which show the stacking conformation of 2 (2S) is more stable that trans conformation (2T) and the stacking conformation of 3 (3S) is less stable that trans conformation (3T). After that, geometrical and energetic features of the intermolecular complex benzene...methylacrylate (4) have also been studied using MPW1B95 method. From our results, we have noticed that both steric and dispersion effects play a key role in the conformational equilibrium of 2.