A luminescent Cd(II)-metal organic frameworks combined of TPT and H₃BTC detecting 2,4,6-trinitrophenol and chromate anions in aqueous

A new luminescence Cd(II)-MOF (1) ([Cd₃(BTC)₂(TPT)(H₂O)₂]·4H₂O, TPT = tris(4-pyridyl)triazine, H₃BTC = 1,3,5-benzenetricarboxylic acid) was successfully synthesized under solvothermal conditions. 1 contains 3D framework which consist of Cd atoms and btc³⁻ anions with the large channels along c axis. Then, tpt ligands locate in the channels by utilizing three N atoms to bridge two Cd1 atoms and one Cd2 atom. 1 not only possesses remarkable thermal stability, but also can steadily exist in different organic solvents and various acid/base solutions (pH = 3–12). Moreover, 1 can detect 2,4,6-trinitrophenol (TNP) and chromate (CrO₄²⁻/Cr₂O₇²⁻) anions with high selectivity and sensitivity in water via the luminescent quenching. The detection limits of 1 for TNP and CrO₄²⁻/Cr₂O₇²⁻ are 6.23 μM and 2.13 μM/2.87 μM. The mechanism of TNP luminescence quenching may be attributed to photoinduced electron transfer and resonance energy transfer, and CrO₄²⁻/Cr₂O₇²⁻ quenching involves resonance energy transfer and competitive absorption of light. Additionally, 1 has the great anti-interference ability and repeatability for detecting TNP and CrO₄²⁻/Cr₂O₇²⁻, which can display the feasibility of this material as a stable luminescent probe in aqueous system.