Reversible Photoluminescence of an H-Bonded Organic Framework Based on Macrocyclic Triazine in Solvation and Desolvation

Reaction of tert-butyl 3,5-diaminobenzoate with cyanuric chloride gave triazine-based macrocycle 1 in 44.3% yield, which was characterized by H-1 and C-13 NMR spectroscopy, mass spectrometry, and elemental analysis. A thermally stable HOF-1 from macrocycle 1 was crystallized from hexane-THF, and its porous property was studied. The crystallographic analysis revealed that the void space was maintained by the pi-pi, H-bond, and C-H-pi interactions between the aromatic moieties in a solid state. The framework changes while losing solvents and produces various emission intensities when irradiated. After completely removing the solvents, the void space of HOF 1 was still available for solvation, and surprisingly, the framework almost recovered after adsorbing solvents according to the powder-XRD study.