Water-stable Eu-MOF fluorescent sensors for trivalent metal ions and nitrobenzene

Abstract

Two novel Eu metal-organic frameworks (MOFs), namely {[Eu(pdba)(HO)]·2HO} (1) and {[Eu(pdba)(HO)]·5HO} (2), were prepared with 4'-(1H-pyrazol-3-yl)-[1,1'-biphenyl]-3,5-dicarboxylic acid (Hpdba) under hydrothermal conditions. MOF 1 exhibits a 3D supramolecular structure assembled from the ππ interactions between the benzene rings of the ligands, whereas 2 comprises a 3D structure through coordination connection between nitrogen atom and Eu. It is worth noting that the two MOFs showed good luminescence performance and high-sensitivity fluorescence quenching behavior toward Fe (Cr) and nitrobenzene. Furthermore, the experimental results for stability in water and cycle test show that these two MOFs can be used as potential fluorescent probes.

Water‐Stable Coordination Polymers as Dual Fluorescent Sensors for Highly Oxidizing Anions Cr2O72− and MnO4−

“…Hence, the combined effect of the competitive absorption and resonance energy transfer could explain the order of quenching constants ( K SV ) and the higher sensitivity of MnO 4 − than Cr 2 O 7 2− , which is also consistent with some previously reported studies . Additionally, the interactions between anions and coordination polymers may also contribute to the quenching effect . Moreover, because both of MnO 4 − and Cr 2 O 7 2− are highly oxidative anions, the the photoinduced electron transfer (PET) mechanism should be considered.…”

A Highly Sensitive and Recyclable Ln‐MOF Luminescent Sensor for the Efficient Detection of Fe3+ and CrVI Anions

“…They not only impart tunable functionality and designable topology, but also exhibit unique luminescence properties, including large Stokes’ shifts, narrow band, high colour purity and relatively long luminescence lifetimes, especially for Tb 3+ and Eu 3+ derivatives . In recently, Ln‐MOFs have gained much attention as fluorescent probes and luminescent bioassays for the detection of cations, anions and small molecules, because of their outstanding luminescence features as well as their uniform pore sizes/environments, unparalleled surface areas, excellent thermal and chemical stability, which are convenient for trapping/adsorbing analytes . Luminescent sensors based on Ln‐MOFs always present unique advanced characteristics such as high stability, operability, and recyclability, as well as high sensitivity and excellent selectivity …”

Fluorescent Sensing Properties of Three Coordination Polymers Constructed by 3,5‐Di(2′,5‐dicarboxylphenyl)pyridine Ligand

“…So, the fluorescence quenching caused by structural collapse has been ruled out. In addition, the UV/Vis absorption spectra of Fe 3+ , Cr 2 O 7 2– and CrO 4 2– solutions show remarkable overlap with the excitation spectra of 1 – 3 between 200 to 450 nm (Figure S13, Supporting Information), which showed that the competition absorption between Fe 3+ , Cr 2 O 7 2– and CrO 4 2– ions in solution and CPs can be responsible for fluorescence quenching . Meanwhile, the nature of electronic‐deficient of metal ions may change the intrinsic transferring path of energy, which results in the fluorescent quenching phenomenon .…”