Theoretical study of π-stacking interaction in a set of cyclophanes

A noncovalent attractive force between two aromatic rings is called π-stacking [1-2]. The stacking interaction between the different moieties in a set of the cyclophanes (Figure 1) has been evaluated computationally using magnetic criteria nucleus independent chemical shift (NICS), magnetic susceptibility, Λ, and harmonic model for aromaticity (HOMA). The study shows that the relative aromaticity of series can dramatically change by the stacking of aromatic moieties