A two-fold interpenetrated zinc–organic framework: luminescence detection of CrO42−/Cr2O72− and chemical conversion of CO2

Abstract

A novel two-fold interpenetrated 3D metal–organic framework {[Zn(DCTP)]·4.2H₂O}_n (1) (H₂DCTP = 4′-(3,5-dicarboxyphenyl)-4,2′:6′,4′′-terpyridine) was synthesized from a pyridine–carboxylic ligand and Zn(OAc)₂ under solvothermal conditions. Along the a-axis, a large pore exists in 1 with a size of 12.5 × 14.7 Å, and after removing solvent molecules, the porosity is 22.4%. Thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD) show that 1 has high thermal, pH, and solvent stability. Importantly, 1 is able to significantly capture CO₂ at up to 67 cm³ g⁻¹ at 273 K. Furthermore, 1 can effectively catalyze the cycloaddition reaction of CO₂ with epoxides, and it can be recycled at least five times without a change in catalytic efficiency. Additionally, 1 can serve as a sensitive and recyclable luminescent probe to detect CrO₄²⁻/Cr₂O₇²⁻, and the detection limit can reach 1 × 10⁻⁶ M and 1.5 × 10⁻⁶ M, respectively.