Highly efficient iodine uptake and iodate selective probe in a 3D honeycomb-like copper–organic framework based on in situ ligand transformation

Abstract

An interesting 3D honeycomb-like fluorescent framework with a 4-connected uninodal unj network with the Schläfli symbol 5⁵·8 was observed in the new polymeric solid, [Cu(L)(H₂O)]·2H₂O (1, L = 4,6-bis(pyridin-4-ylcarbamoyl)isophthalate), based on in situ ligand transformation from the weak acidic solvothermal reaction of copper nitrate trihydrate with N′-bis(4-aminopyridine)phenylenediimide. Its structure crystallized in the chiral hexagonal P6₅22 space group, with Z = 6 (a = 18.8181(8) Å, c = 23.6351(7) Å, V = 7248.4(7) ų) from X-ray crystallography analysis. This copper-organic framework not only exhibits a remarkable uptake performance toward I₂ vapor with a maximum adsorption capacity of 3410 mg g⁻¹ but also displays an excellent fluorescence selective recognition capability on IO₃⁻ achieving a lower LOD value of 17 μM.