Evidence of preferential π-stacking: a study of intermolecular and intramolecular charge transfer complexesElectronic supplementary information (ESI) available: Detailed description of synthesis, MS, IR 1H-NMR, 13C-NMR, optical spectra, and Rehm–Weller analysis. See DOI: 10.1039/c0cc00249f

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. [ABSTRACT FROM AUTHOR]