A Simple Rotor Guest Molecule Mediates the Formation of Cage or Channel Structures of Halogen-Bonding Host Cocrystals

Rotor molecules can be used to direct supramolecular self-assembly, and the electronic spectroscopic behaviors of these rotors have become widely researched topics in chemistry and materials science. Herein, simple 2-phenylpyridine (oPP) and biphenyl linear rotors are used to construct host–guest cocrystals by halogen bonds and π–hole bonds. Hexagonal cage-type and hexagonal channel-type host structures are constructed under the mediation of the same rotor guest, oPP, with dihedral angles of 4.2° and 13.7°, respectively, by the cooperation of different noncovalent interactions, such as C–I···–O–N+ halogen bonds, π–hole···π bonds, C–H···F, and C–H···π hydrogen bonds, during crystallization. Moreover, the twisted state of the rotor guest in the hexagonal cage-type or channel-type host structures exerts remarkable influence on the luminescence of ternary cocrystals, which display light purple and bright orange colored luminescence, respectively, under a radiation of 365 nm. The work presented in this paper has remarkable significance for obtaining host structures with cavity or channel characteristics caused by the manifold configuration of guest moieties, which can be used to diversify supramolecular architectures. The formation of new crystalline polymorphs directed by rotor molecules with different dihedral angles, as described herein, provides an avenue for developing new smart multicomponent luminescent materials, molecular machines, and molecular electronics.