Four New Stable Lanthanide Organic Frameworks: Highly Selective Luminescent Sensing and Magnetic Properties

Abstract

Four new two-dimensional isostructural lanthanide metalorganic frameworks {[Ln(L)(LH)(H 2 O) 2 ]·H 2 O} n (1-Ln; Ln= Sm, Eu, Tb and Dy) were successfully assembled under hydro(solvo) thermal conditions by Ln 3 + salts and 4-(3-carboxyl-1,2,4-1Htriazol-1-yl) benzoic acid (H 2 L). Compounds are isostructural and display a 2D 3-connected fes 2-periodic net with the point symbol of (4·8 2 ). Thus, 1-Eu was chosen as a probe for sensing different metal ions and anions due to the excellent luminescence and good luminescent stability in water. 1-Eu shows high selectivity for Fe 3 + , Cr 2 O 7 2À and CrO 4 2À ions, indicating that 1-Eu should be an excellent candidate for luminescence sensing material. Furthermore, antiferromagnetic exchange couplings between the neighbouring Dy 3 + ions exist in 1-Dy.[a] Dr.

Isostructural Lanthanide Coordination Polymers with High Photoluminescent Quantum Yields by Effective Ligand Combination: Crystal Structures, Photophysical Characterizations, Biologically Relevant Molecular Sensing, and Anti-Counterfeiting Ink Application

“…The distortion of the Ln III configuration is more favorable for the electric transition responsible potentially for the enhanced emissions . All the bond lengths involved in the Tb ion (Table S1) are commensurable to those previous reported Tb III -derived complexes with various N- and/or O carboxylate -containing organic ligands. − As a rigid heterocyclic ligand, the monodeprotonated TPA – anion provides one N triazolyl , one N pyridyl , as well as one O carboxylate donors to chelate and bridge two Tb III ions in a μ 2 -η 1 :η 1 :η 2 mode (Figure S1). Instead, both doubly deprotonated ox 2– ligands with slightly different torsion angles (164.7°/168.3° vs 180°/180°) are centrosymmetric, adopting a tetradentate μ 2 -η 1 :η 1 :η 1 :η 1 fashion (Figure S1).…”

Nickel(II)-Based Two-Dimensional Coordination Polymer Displaying Superior Capabilities for Selective Sensing of Cr(VI) Ions in Water

“…Notably, the detection limits were calculated to be 1.39 ppb (for Cr 2 O 7 2– ) and 0.09 ppb (for CrO 4 2– ), which are remarkably lower than the corresponding ones observed for ppvppa and some reported compounds (Table S4). ,− The framework of 3 remained intact after exposure to Cr 2 O 7 2– and CrO 4 2– as confirmed by PXRD patterns (Figure S12). Luminescence could be regenerated when solid sample 3 was centrifuged from the solution containing these analytes.…”

“…The detection limits for the most efficient complex 3 were 1.39 ppb for Cr 2 O 7 2– (pH = 4) and 0.09 ppb for CrO 4 2– (pH = 12), which are well below the permissible limits for these anions set by the United States Environmental Protection Agency and the European Union and the lowest so far reported for functional CPs-based sensing materials (Table S4). ,− Our present work provided interesting insight into the assembly of the most fluorescent CP-based sensing materials from rationally designed organic linkers and suitable metal ions and revealed the great potential for the luminescent detection of hazardous metal ions in wastewater by using these sensors.…”

“…The fluorescent quenching of 1 – 3 by these anions was similar to that reported for other fluorescent CPs (Table S4). − Compounds 1 – 3 can detect Cr 2 O 7 2– and CrO 4 2– in solution, and thus there was a potential for them to be used as chemical sensors for the detection of such important pollutants in water.…”

A Recyclable bi‐functional Luminescent Zinc (II) metal–organic framework as highly selective and sensitive sensing probe for nitroaromatic explosives and Fe3+ ions

“…In recent years, various detection approaches have been put into use, including energy‐dispersive X‐ray diffraction, ion mobility spectrometry (IMS), Raman spectroscopy, gas chromatography coupled with mass spectrometry, but they are generally high cost and often not easily portable . Fluorescence quenching method has already been proven to be a feasible method for the sensing of toxic pollutants …”