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

Abstract

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⁻.

Keywords:

• Zn(II) coordination polymer
• (R)-2-(1-carboxyethoxy)terephthalic acid ligand
• fluorescent probe
• high sensitivity
• selective ion recognition

Disclosure statement

The authors declare no competing financial interest.

Additional information

Funding

This work accepted financial support from National Natural Science Foundation of China (21761036), Science and Technology Foundation of Guizhou Province (ZK2022576), and High-Level Talent Foundation of Hechi University (2019GCC008).