Role of CH-π interaction energy in self-assembled gear-shaped amphiphile molecules: correlated ab Initio molecular orbital and density functional theory study

摘要

Ab initio molecular orbital and density functional theory calculations with inclusion of dispersion interaction effect are employed to reveal the characteristic features of intermolecular interactions for the molecular capsule (16) consisting of six gear-shaped amphiphile molecules (1) discovered by Hiraoka et al. (J Am Chem Soc 130:14368-14369, 2008). The contributions of CH-ti and π-π type dispersion energies are found to be indispensable for the formation of hexameric capsule 16 by the analysis of decomposed interaction energies between fragmented-model species in the 1 molecule. We have also calculated the hexameric capsule (26) from demethylated 1 molecule (2). Such subtle structural difference induces the different characters of intermolecular interactions, in which the stabilization energy of hexameric 26 capsule is about 40 kcal/mol smaller than that of the original 16 capsule, due to the lack of three methyl groups for the CH-π interactions in 2 molecules.