Ab initio study of [n.n]paracyclophane (n=2, 3) complexes with cations:: Unprecedented through-space substituent effects

Several cation-pi A complexes between substituted [n.n]paracyclophanes (n = 2, 3) and cations have been studied using high level ab initio calculations. The chemical substitution at the aromatic ring that is not interacting with the cation has a strong influence upon the binding energy. This strong through-space substituent effect has been studied using the atoms-in-molecules theory, which has been found useful to explain the energetic results.