Constructions of new luminescent 3D porous MOFs with high stability, unique selectivity and low detection limits for various ions in aqueous solution
Abstract
Three new luminescent metal-organic frameworks (MOFs), {[Zn(L)(H2O)]·2H2O}n (1), {[Pb(L)]·0.5DMA}n (2), and {[Cd2(L)2(H2O)2]·2H2O}n (3) were synthesized by an asymmetric N-containing 2-pyrimidin-5-yl-terephthalic acid (H2L) ligand with Zn2+, Pb2+, and Cd2+ ions, respectively. In these complexes, L2- ligand exhibits the multiple coordination modes with metal ions to form different new structures; especially there exist the different secondary building units (SBUs) in 2 and 3. The solid-state luminescent properties of complexes 1-3 were studied at room temperature and the mechanism was analyzed carefully. In particular, complex 2 has good stability in aqueous solution and exhibits the specific selectivity and sensitivity to probe Fe3+, MnO4-, CrO42- and Cr2O72- simultaneously, and the detection limits of Fe3+ and Cr2O72- ions are 5.6 × 10-5 and 10-6, respectively. These are lower than those of other reported sensors. Finally, its quenching mechanism has also been studied in detail.
- Publication:
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Journal of Solid State Chemistry France
- Pub Date:
- May 2020
- DOI:
- 10.1016/j.jssc.2020.121270
- Bibcode:
- 2020JSSCh.28521270J
- Keywords:
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- MOFs;
- SBUs;
- Water stability;
- Fluorescence sensing;
- Low detection limits