Isostructural Tb³⁺/Eu³⁺ Co-Doped Metal–Organic Framework Based on Pyridine-Containing Dicarboxylate Ligands for Ratiometric Luminescence Temperature Sensing

Abstract

In this work, we prepared two types of isostructural Ln 3+ -based metal−organic frameworks (LnMOFs) under solvothermal conditions, where two structurally similar pyridine-containing dicarboxylate ligands, 6-(4-carboxyphenyl)nicotinic acid and [2,2′-bipyridine]-5,5′-dicarboxylic acid, were used as the organic linkers. The as-synthesized LnMOF compounds were characterized using single-crystal X-ray diffraction (XRD), powder XRD, and thermogravimetric analysis. With the lanthanide co-doping approach, two mixed LnMOFs, Tb 0.95 Eu 0.05 cpna and Tb 0.95 Eu 0.05 bpydc, were obtained and evaluated for application as potential ratiometric luminescence thermometers. The temperature-dependent luminescence of the two materials was investigated, and their emission intensities, luminescence lifetimes, and thermometric parameters were compared. They exhibit an excellent S-shaped response for temperatures in the range of 25−300 K, with favorable relative sensitivity and temperature uncertainty. Moreover, their color changes from green at 25 K to red at 300 K, so that they are also suitable as colorimetric luminescent probes.

Hydrothermal Synthesis and Up‐conversion Luminescence of Ho3+/Yb3+ Co‐doped PbTiO3

“…However, these mentioned sensors have some limitations, for their large size, use of electrical modules, invasiveness and so on. To overcome these weaknesses, luminescence‐based materials, including up‐conversion RE‐oxide materials and lanthanide metal‐organic frameworks (LnMOFs), have been explored to use as temperature sensing for their unique advantages of contactless measurement and large‐scale imaging , …”

Synthesis, Structure, and Properties of Cadmium(II) Centered Chiral Coordination Polymer based on (R)‐6‐(1‐Carboxyethoxy)‐2‐naphthoic Acid

“…For example, Qian's report proposes Tb‐based MOF for luminescence detection of uric acid. And Eu‐based MOF sensing research for explosive picric acid . In addition, the d 10 center coordination polymer has been studied because it exhibits excellent luminescence ability in combination with functional ligands.…”

Energy Transfer in Metal–Organic Frameworks and Its Applications

“…Zhao et al demonstrated that different numbers of pyridine units in the ligand resulted in a ligand with different T 1 state energy values and changed the sensitization efficiency of Ln 3+ . [ 50 ] Specifically, the QY of Tb‐bpydc, with its two pyridine units, exhibits twofold higher activity than Tb‐cpna, which had only one pyridine unit. The result indicates that modifying the pyridine unit in the ligand enhances the ligand's sensitization for Tb 3+ , as evidenced by the improved Tb 3+ ‐to‐Eu 3+ EnT efficiency.…”