Coordination polymers based on di-9,10-(pyridine-4-yl)-anthracene: selective adsorption of CO2 and fluorescent properties

Abstract

In this study, we report four coordination polymers based on di-9,10-(pyridine-4-yl)-anthracene (dpa). 1 and 2 are similar 2-fold interpenetrating pcu networks built by Co²⁺, dpa and dicarboxylate ligands of different lengths, and the porosities and pore sizes of the interpenetrated frameworks were adjusted. 1 contains 1D channels of a cross-section of 3.7 × 3.7 Å and exhibits very high selectivity in adsorbing CO₂ over N₂. The channels in 2 are larger (5.1 × 5.1 Å) but unstable upon removing solvent guests. 3, [Cd(dpa)₂(Cl)₂]_n·2nDMF, contains layer structures constructed by dpa, Cd²⁺ and Cl⁻ atoms. 4, [Cd(dpa)(Cl)₂(H₂O)₂]_n, contains polymeric chains with Cd²⁺ atoms linked by dpa ligands. 3 and 4 showed strong fluorescent emissions, and mixed matrix membranes prepared based on 3 or 4 showed very high sensitivity and selectivity for detecting Cr₂O₇²⁻ in water.