Substituent and heteroatom effects on parallel-displaced pi-stacking: Further evidence that short-range pi-pi interactions are not under electrostatic control

Stacking interactions are a recurring motif in supramolecular chemistry and biochemistry, where a persistent theme is a preference for parallel-displaced aromatic rings over face-to-face pi-stacking. The Hunter-Sanders model purports to explain this preference in terms of quadrupolar electrostatics but that interpretation is inconsistent with accurate quantum-mechanical calculations.... Show more