Computational Study of Janusene/Crown as Model for Designing Molecular On/Off Switches by Host-Guest Chemistry

Abstract

The janusene platform capped with a tetraethylene glycol moiety (JAN/crown) was employed as a model system to examine noncovalent interactions in its host-guest (H-G) complexes with various types of cationic and neutral guests. The spaces between the cofacial aromatic rings (interannular space) and the crown cavity were considered as inclusion regions, and the relative stabilities of both types of complexes were evaluated computationally. The interannular complexes proved to be less stable as compared to crown complexes, likely due to the required distortion in the JAN skeleton in order to accommodate the host. The possibility to design molecular on/off switches by migration of the cationic host from inside the crown cavity (the “off” switch) to the cofacial region between π-stacked rings (the “on” switch) was analyzed.