Parallel face-to-face arene–arene binding energies between benzene and multi-halo substituted aromatics and between tyrptophan and multi-halo substituted aromatics were calculated at the MP2(full)/6-311G ∗∗ level of theory. A correlation was investigated between the binding energy and either the quadrupole moment (Θ zz ) or the sum of the Hammett substituent constant σ p (∑σ p ) of the substituted aromatic. For both benzene and tryptophan, an excellent correlation was found between the calculated binding energy with multi-halo substituted aromatics and the sum of the ∑σ p values of the substituted aromatics.