A new Cd based metal–organic framework for quick and convenient detection of trace water in isopropanol and 1,4-dioxane

Abstract

A new Cd-MOF ([Cd(py)(L)(H₂O)₂], 1) based on a fluorescent brightener (Na₂L, disodium 4,4′-bis(2-sulfonatostyryl)biphenyl) was synthesized by a hydrothermal method. 1 emits weak fluorescence, but it can partially dissociate in a few seconds when encountering water, releasing L²⁻ ligands with a strong luminescence. The luminescent color of the L²⁻ aqueous solution is different from that of L²⁻ in other organic solvents, which makes 1 capable of detecting trace amounts of water in isopropanol and 1,4-dioxane. Compared to the MOFs currently used to detect trace amounts of water in organic solvents, 1 is simpler to produce, cheaper in raw materials and higher in sensitivity (v/v, <0.01%). Furthermore, a test paper has been made from 1 for the rapid detection of trace amounts of water. And the detection process has no special requirements of the surrounding environment, making 1 a rapid sensor for trace amounts of water in organic solvents.