Solvent-induced construction of two zinc metal–organic frameworks for highly selective detection of nitroaromatic explosives

Two novel zinc metal–organic frameworks [Zn₃(TPT)₂(DMF)₂]·0.5HNMe₂ (1) and NH₂Me₂·[Zn(TPT)]·DMF (2) have been synthesized by using Zn(II) ions and p-terphenyl-3,4′′,5-tricarboxylic acid (H₃TPT). The structures of these two MOFs are dependent on the solvents used in the synthetic processes. Compound 1 was synthesized in a mixture of DMF and H₂O, while compound 2 was obtained in the presence of DMF and ethanol. The three-dimensional (3D) framework of 1 is constructed by the connection of Zn–carboxylate chains and TPT³⁻ linkers. The structure of 2 can be described as a 3,6-connected network based on the assembly of binuclear zinc clusters and TPT³⁻ ligands. These two MOFs exhibit ligand-based photoluminescence at around 375 nm, as well as high efficiency for the recyclable detection of nitroaromatic explosives.