Intermolecular interactions between halo‐substituted p‐benzoquinones (BQ) and halide anions were examined in solution, solid‐state and/or in silico. While X‐ray crystallography revealed only halogen bonding (XB) between tetraiodo‐p‐benzoquinone (I4Q) and halides, the results of a UV‐Vis study in solutions were consistent with the formation of 1 : 1 anion‐π complexes. DFT computations showed that the anion‐π complexes of halides with most halo‐substituted BQ molecules were more stable (by 2–7 kcal/mol) than their XB analogues, but the stabilities of different complexes of I4Q were essentially the same. Thus, the structural features of the co‐crystals with I4Q were related to multicenter XB interactions between BQs and halides, thus leading to the formation of 3D networks. The observation of anion‐π complexes in solutions was attributed to their higher molar absorptivity (by more than an order of magnitude) than that of their XB analogues. Overall, the stabilities of anion‐π and XB complexes between BQs and halides were well correlated with the values of highest electrostatic potentials on the surfaces of BQ molecules when their polarizations were taken into account.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.