Synthetic approaches for accessing rare-earth analogues of UiO-66

Rare-earth (RE) analogues of UiO-66 with non-functionalised 1,4-benzenedicarboxylate linkers are synthesised for the first time, and a series of synthetic approaches is provided to troubleshoot the synthesis. RE-UiO-66 analogues are fully characterised, and demonstrate a high degree of crystallinity, high surface area and thermal stability, consistent with the UiO-66 archetype

Tuning the rare-earth UiO-66 metal–organic framework platform for white light emission

Metal–organic frameworks (MOFs) have received notable attention owing to their structural diversity, permanent porosity, and high surface areas. In addition to these properties, rare-earth (RE) MOFs have the added feature of tunable photoluminescence dictated by the identity of the metal ion and organic linker in the RE-MOF. Herein, we explore the tunable photoluminescent properties of RE-UiO-66 by synthesizing and characterizing mono-, bi- and tri-metal RE-UiO-66 analogues where RE = Tb(III), Gd(III), and Eu(III), to ultimately design a white light emitting MOF. The photophysical properties of this series of MOFs are explored and, as a proof of concept, the tri-metal Tb:Gd:Eu-UiO-66 is used as a surface coating on a UV light emitting diode (LED) to give a white light emitting device

Unravelling the synthesis of a rare-earth cluster-based metal–organic framework with spn topology

Y-CU-45, an analogue of Zr-MOF-808, is synthesized for the first time. Several reaction conditions are tested demonstrating that two fluorinated modulators are required for a reproducible synthesis yielding high quality material. Y-CU-45 shows high crystallinity and surface area, shining light on the potential for rare-earth cluster-based MOFs with open metal sites

Unravelling the synthesis of a rare-earth cluster-based metal–organic framework with spn topology

Y-CU-45, an analogue of Zr-MOF-808, is synthesized for the first time. Several reaction conditions are tested demonstrating that two fluorinated modulators are required for a reproducible synthesis yielding high quality material. Y-CU-45 shows high crystallinity and surface area, shining light on the potential for rare-earth cluster-based MOFs with open metal sites

A Simple Method for Teaching Bragg’s Law in an Undergraduate Teaching Laboratory with the use of Metal–Organic Frameworks

Metal–organic frameworks (MOFs) are a class of porous materials that are often crystalline with high surface area and structural tunability. In this laboratory experiment designed for inorganic chemistry students at the undergraduate level, students complete a two-step experiment where they will first (i) synthesize two isostructural zirconium-based MOFs, UiO-66 and UiO-67, and then (ii) isolate and characterize the materials using powder X-ray diffraction (PXRD). A simple solvothermal procedure was developed for the synthesis of UiO-66 and UiO-67 using the air/moisture stable zirconyl chloride octahydrate as a starting reagent. Depending on the equipment available, the MOFs can be further characterized by nitrogen adsorption analysis for surface area determination using Brunauer–Emmett–Teller (BET) theory, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), thermogravimetric analysis (TGA), 1H nuclear magnetic resonance (NMR) spectroscopy, and scanning electron microscopy (SEM). Upon synthesizing the MOFs and collecting the characterization data, students analyze and describe their results by answering a series of questions included in the laboratory manual. This exercise will allow students to develop practical laboratory skills while expanding their knowledge on some fundamental concepts in inorganic chemistry, materials chemistry, MOFs, crystallography, and other characterization techniques as availability allows

Modulating Photo- and Radioluminescence in Tb(III) Cluster-Based Metal–Organic Frameworks

Luminescent metal–organic frameworks (MOFs) are of interest for sensing, theranostics, dosimetry, and other applications. The use of lanthanoids in MOF metal nodes allows for intrinsic met-al-based luminescence. In this work, a facile route for modulat-ing the photoluminescent and radioluminescent properties of Tb(III)-based MOFs is reported. By using Tb(III)-cluster nodes as X-ray attenuators, and organic linkers with varying excited state energies as sensitizers, MOFs with metal-based, linker-based, and metal+linker-based photo- and radioluminescence are reported

Adsorptive Removal of Iodate Oxyanions from Water using a Zr-based Metal–Organic Framework

A Zr6-based metal–organic framework (MOF), MOF-808, is investigated for the adsorptive removal of IO3⁻ from aqueous solutions, due to its high surface area and abundance of open metal sites. The uptake kinetics, adsorption capacity and binding mode are studied, showing a maximum uptake capacity of 233 mg/g, the highest reported by any material

Adsorptive removal of iodate oxyanions from water using a Zr-based metal–organic framework

A Zr$_6$-based metal–organic framework (MOF), MOF-808, is investigated for the adsorptive removal of IO$_3$− from aqueous solutions, due to its high surface area and abundance of open metal sites. The uptake kinetics, adsorption capacity and binding mode are studied, showing a maximum uptake capacity of 233 mg g$^{−1}$, the highest reported by any material

Synthesis, characterization and photophysical properties of a new family of rare-earth cluster-based metal–organic frameworks

In this work, nine new rare-earth metal–organic frameworks (RE-MOFs, where RE = Lu(III), Yb(III), Tm(III), Er(III), Ho(III), Dy(III), Tb(III), Gd(III), and Eu(III)) isostructural to Zr-MOF-808 are synthesized, characterized, and studied regarding their photophysical properties. Materials with high crystallinity and surface area are obtained from a reproducible synthetic procedure that involves the use of two fluorinated modulators. At the same time, these new RE-MOFs display tunable photoluminescent properties due to efficient linker-to-metal energy transfer promoted by the antenna effect, resulting in a series of RE-MOFs displaying lanthanoid-based emissions spanning the visible and near-infrared regions of the electromagnetic spectrum