Columnar/Lamellar Packing in Cocrystals of Arylbipyridines with Diiodoperfluorobenzene

Abstract

Stimulated by strongly directional C-I⋯N noncovalent halogen bonding, π-hole⋯π and π-π interactions, cocrystals of nonplanar 4-arylated-2,2′-bipyridine (ArB) derivatives with 1,4-diiodo-tetrafluorobenzene (D) were generated which exhibit a promising columnar/lamellar packing arrangement. Hirshfeld surface, quantum theory of atoms in molecules, and electrostatic potential surface analyses were employed to examine the weak intermolecular interactions governing the packing arrangement in ArB crystals and corresponding cocrystals with D (ArB·D). Cocrystals of 4-phenyl-2,2′-bipyridine (PhB) and 4-(naphthalen-1-yl)-2,2′-bipyridine (NaB) with D [PhB·D1, PhB·D2, (NaB)2·D2.5, and (NaB)3·D2] exhibited C-I⋯N directed infinite one-dimensional chains of alternate ArB and D units. In contrast, C-I⋯N interactions guide the formation of termolecular complexes in the cocrystal of 4-(phenanthren-9-yl)-2,2′-bipyridine with D (PhenB·D0.5). Successful implementation of C-I⋯N interactions aided by 2,2′-bipyridine and D enabled the tuning of three-dimensional close packing in planar polyaromatic hydrocarbons into a columnar/lamellar arrangement suitable for optoelectronic devices.