Mixed matrix membranes based on fluorescent coordination polymers for the detection of Cr2O72− in water

Abstract

In this work, three coordination polymers (CPs) were synthesized from Zn²⁺/Cd²⁺, fluorescent di-9,10-(imidazolyl)-anthracene (dia), and cyclohexane-1,4-dicarboxylic acid (H₂cda). The coordination polymer 1, [Zn(dia)(cda²⁻)_0.5(Hcda⁻)·0.5H₂O]_n, contained a layered structure. The coordination polymer 2, [Zn(dia)(cda²⁻)]_n, contained a rare 3D network with a self-catenation pattern. The coordination polymer 3, [Cd₂(dia)_1.5(cda²⁻)₂]_n, contained a 3D network of ose topology. Coordination polymers 1, 2 and 3 were all highly fluorescent. Mixed matrix membranes, prepared by dispersing particles of 1, 2 or 3 within a matrix of polymethyl methacrylate, showed high sensitivity, selectivity and recyclability for detecting Cr₂O₇²⁻ in water.