Fluorescent Zn(II) coordination polymer constructed by (R)-2-(1-carboxyethoxy)terephthalic acid as a probe for selective identification of Cr2O72− and MnO4−.

Ligand (R)-2-(1-carboxyethoxy)terephthalic acid ((R)-H₃CTA) with excellent fluorescence has been prepared from (S)-methyl lactate and 2-hydroxyterephthalic acid. With the help of 4,4′-bipyridine (4,4′-BIP), (R)-H₃CTA assembled with Zn²⁺ to obtain {[Zn((R)-CTA)(4,4′-BIP)₂] · H₂O}_n (HU13-R) under hydrothermal conditions. In HU13-R, (R)-CTA³⁻ anions and Zn(II) centers resulted in a (R)-CTA-Zn layer, and then adjacent (R)-CTA-Zn layers and 4,4′-BIP ligands further formed a typical pillared-layer structure with a (3,5)-connected net. Besides excellent water stability, HU13-R has strong solid-state fluorescence. As a bright luminescent material, detection limit from HU13-R is up to 3.22 × 10⁻⁶ M for Cr₂O₇²⁻ and 5.92 × 10⁻⁶ M for MnO₄⁻, showing high sensitivity for anions. The presence of different anions does not interfere with its recognition ability for Cr₂O₇²⁻ and MnO₄⁻. [ABSTRACT FROM AUTHOR]