Evidence of preferential π-stacking: a study of intermolecular and intramolecular charge transfer complexes

Abstract
Nine combinations of π-electron donors and acceptors were examined by UV-vis, fluorescence and 1H-NMR spectroscopy to identify π-stacked charge transfer complexes in macromolecular and supramolecular constructs. The high association constant of pyrene and naphthalene diimide suggests a preferentially π-stacking pair rationalized by frontier orbital congruence.