Four Novel Lanthanide(III) Metal–Organic Frameworks: Tunable Light Emission and Multiresponsive Luminescence Sensors for Vitamin B₆ and Pesticides

Abstract

Four novel lanthanide­(III)-based metal–organic frameworks (MOFs), formulated as [Ln3(HDDB)­(DDB)­(H2O)6]­·NMP·3H2O (Ln = Eu (1), Tb (2), Dy (3), Gd (4)), were successfully constructed with a rigid pentacarboxylate ligand 3,5-di­(2′,4′-dicarboxylphenyl) benzoic acid (H5DDB). Complexes 1–4 are isostructural and exhibit a new 3,4,4,6-connected network. 1–2 exhibit excellent fluorescence properties and good water stability. The emissions of the doped bimetallic Eu x Tb1–x -MOFs can be adjusted by varying the Eu­(III)/Tb­(III) ratios used in the reaction. Furthermore, 2 presents excellent sensitivity and selectivity to sense vitamin B6 (VB6) and the pesticide 2,6-dichloro-4-nitroaniline (DCN) as a multiresponsive luminescent sensor. Compound 2 is the first MOF-based luminescent sensor for detecting VB6 with a low detection limit (LOD) of 9.5 × 10–8 M (∼58.4 ppb) in phosphate buffer solution (pH = 6.86), which also displays a high-sensitivity sensing activity for VB6 in human serum. Moreover, 2 exhibits high-sensitivity sensing for the pesticide DCN with an LOD value of 1.4 × 10–7 M (∼86.1 ppb) in aqueous solution, and it also can be successfully used for detecting DCN in the extracts of carrots, grapes, and nectarines.

Highly pH-Stable Ln-MOFs as Sensitive and Recyclable Multifunctional Materials: Luminescent Probe, Tunable Luminescent, and Photocatalytic Performance

“…However, when the concentration of Eu 3+ ions is 10%, the characteristic emission peaks are much stronger, which may be due to the easier energy transfer between Tb 3+ and Eu 3+ ions. In addition, the luminescence colors of doped Ln-MOFs varied from green to red under the irradiation of UV-light (254 nm) (Figure b), which were consistent with the CIE coordinates (Figure S8) and other report doped Ln-MOFs. , …”

“…In addition, the luminescence colors of doped Ln-MOFs varied from green to red under the irradiation of UV-light (254 nm) (Figure 3b), which were consistent with the CIE coordinates (Figure S8) and other report doped Ln-MOFs. 48,49 Sensing of Metal Ions. Considering the good stability and luminescence performance of 1-Tb in water, we studied the sensing characteristics of 1-Tb to different ions in aqueous solution.…”

Temperature-Induced Structural Transformations of Lanthanide Coordination Polymers Based on a Semirigid Tricarboxylic Acid Ligand: Crystal Structures and Luminescence Properties

“…Solvents can accept several roles in the construction of CPs, for example, ligand, guest, both ligand and guest, or template. Meantime, temperature can also affect the morphology, coordination geometry of metal center, dimension, and topology, configuration transformation of flexible organic or semirigid ligand by increasing the reaction rate, the pressure of the reaction system. − …”

Rapid and reliable triple-emissive detection of 2,6-dichloro-4-nitroaniline as a pesticide based on a high-nuclear Cd(ii)–Sm(iii) nanocluster

“…18,19 Some visible luminescent Eu-and Tb-MOFs have been employed to detect DCN. 20,21 To our knowledge, so far there are no reports on the use of high-nuclear lanthanide-based clusters as luminescent sensors for the detection of DCN.…”