Co-crystallization of benzothiazole via halogen and hydrogen bonding: crystal structure and photoluminescence properties

Abstract

Heterocyclic compounds are effective frameworks for solid-state light-emitting materials because of their ability to undergo various intermolecular interactions. Benzothiazole (BTZ) is a promising heterocyclic light-emitting material, which typically exists as a liquid; this limits its solid-state applications and requires introducing additional substituents. To overcome this limitation, we employed a co-crystallisation technique to solidify pure BTZ. We successfully formed BTZ cocrystals with 1,4-diiodotetrafluorobenzene, pentafluorophenol, and pentafluorobenzoic acid. Hydrogen and halogen bonding effectively immobilised the liquid BTZ within the crystal lattice, stabilising it in the solid state. This approach enabled us to elucidate the intrinsic photophysical properties of BTZ and provided a new strategy for designing solid-state organic light emitters.