Photophysical Properties of Rare-Earth Cluster-Based Metal–Organic Frameworks

The work described herein explores the field of metal–organic frameworks (MOFs) with a particular emphasis on rare-earth (RE) cluster-based MOFs. MOFs are materials that are of interest due to their permanent porosity, high surface areas, and tunable structures. This thesis focuses on three different MOFs: RE-UiO-66 (UiO = University of Oslo), RE-CU-10 and RE-CU-27 (CU = Concordia University). The synthesis, characterization, and photophysical properties of these MOFs are presented. Chapter 2 explores tuning of the RE-UiO-66 platform by synthesizing and characterizing mono-, bi- and tri-metal RE-UiO-66 analogues where RE = Tb(III), Gd(III), and Eu(III), ultimately leading to the formation of a white light emitting MOF. Furthermore, a study of the photophysical properties of this series of MOFs is conducted and as a proof of concept, Tb:Gd:Eu-UiO-66 is deposited on a UV light emitting diode (LED), leading to a white light emitting diode (WLED). Chapter 3 describes a facile route for modulating the photoluminescent and radioluminescent properties of Tb(III) cluster-based MOFs. By using Tb(III)-cluster nodes as Xray 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

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

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