Metal–organic frameworks (MOFs) display a wide range of luminescent behaviors resulting from the multifaceted nature of their structure. In this critical review we discuss the origins of MOF luminosity, which include the linker, the coordinated metal ions, antenna effects, excimer and exciplex formation, and guest molecules. The literature describing these effects is comprehensively surveyed, including a categorization of each report according to the type of luminescence observed. Finally, we discuss potential applications of luminescent MOFs. This review will be of interest to researchers and synthetic chemists attempting to design luminescent MOFs, and those engaged in the extension of MOFs to applications such as chemical, biological, and radiation detection, medical imaging, and electro-optical devices (141 references).

Luminescent Metal–Organic Frameworks

Lanthanide-based luminescent hybrid materials.

Interpretation of europium(III) spectra

Cerium dioxide (CeO2, ceria) is becoming an ubiquitous constituent in catalytic systems for a variety of applications. 2016 sees the 40th anniversary since ceria was first employed by Ford Motor Company as an oxygen storage component in car converters, to become in the years since its inception an irreplaceable component in three-way catalysts (TWCs). Apart from this well-established use, ceria is looming as a catalyst component for a wide range of catalytic applications. For some of these, such as fuel cells, CeO2-based materials have almost reached the market stage, while for some other catalytic reactions, such as reforming processes, photocatalysis, water-gas shift reaction, thermochemical water splitting, and organic reactions, ceria is emerging as a unique material, holding great promise for future market breakthroughs. While much knowledge about the fundamental characteristics of CeO2-based materials has already been acquired, new characterization techniques and powerful theoretical methods are dee...

Fundamentals and Catalytic Applications of CeO2-Based Materials

Advanced oxidation processes (AOPs), defined as those technologies that utilize the hydroxyl radical (·OH) for oxidation, have received increasing attention in the research and development of wastewater treatment technologies in the last decades. These processes have been applied successfully for the removal or degradation of toxic pollutants or used as pretreatment to convert recalcitrant pollutants into biodegradable compounds that can then be treated by conventional biological methods. The efficacy of AOPs depends on the generation of reactive free radicals, the most important of which is the hydroxyl radical (·OH). The authors summarize the formation reactions of ·OH and the mechanisms of pollutants degradation. They cover six types of advanced oxidation processes, including radiation, photolysis and photocatalysis, sonolysis, electrochemical oxidation technologies, Fenton-based reactions, and ozone-based processes. Controversial issues in pollutants degradation mechanism were discussed. They review t...

Advanced Oxidation Processes for Wastewater Treatment: Formation of Hydroxyl Radical and Application

A novel europium complex, [Eu(AClBA)3(H2O)2·H2O]2, where AClBA = 5-amino-2-chlorobenzoic acid, has been characterized structurally by X-ray diffraction methods. The complex has a dimeric structure formed by bridging oxygen atoms of carboxylate groups. It is triclinic, space group , with a = 9.849(3), b = 11.000(3), c = 12.790(4) A, α = 106.828(4), β = 103.588(4), γ = 93.493(4)°, V = 1276.7(6) A3, D c  = 1.867 Mg m−3, Z = 1, F(000) = 708, goodness-of-fit = 1.034, R1 = 0.0283. Photophysical properties (UV absorption, excitation and emission) of the complex have been determined.

A novel dimeric europium complex of 5-amino-2-chlorobenzoic acid: Structure and photophysical properties

Dysprosium ion activated RE3BO6 (RE = La, Y, Gd) polycrystalline phosphors have been prepared via a modified sol–gel process with urea as fuel and rare earth nitrates as precursors. The crystal phase and the morphology of the phosphors are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The average particle size after heat treatment at 1,000 °C is around 5 μm by particle size determination technique. The characteristic transitions of Dy3+ due to 4F9/2 → 6H15/2 (blue) and 4F9/2. → 6H13/2 (yellow) can be observed in the emission spectra and the yellow-to-blue intensity ratio (Y/B) can be changed with the variety of the doped concentration of Dy3+ ion. Zeta potential shows the relationship between the surface charges to the pH value in suspension.

Sol–gel preparation and luminescence of RE 3 BO 6 : Dy 3+ (RE = La, Y, Gd) microparticles with hybrid precursors

Amorphous RE–Fe–B–Na colloidal nanoparticles: High temperature solution synthesis and magnetic properties

Eu3+/Sm3+ hybrids based with 8-hydroxybenz[de]anthracen-7-one organically modified mesoporous silica SBA-15/16

In the present work, a novel functional molecular bridge (PASi) is achieved through the modification of ortho phthalic anhydride (PA) by N-2-aminoethyl-3-aminopropyl-methyl-dimethoxylsiliane (abbreviated as AEAPMMS). The PASi plays the role of a functional bridge to link Eu3+ (Tb3+) through the oxygen atom to a Si–O network formed from tetraethoxysilane. Subsequently, a novel chemically bonded hybrid material with double chemical bonds (RE–O coordination bond and Si–O covalent bond) has been fabricated. The characteristic red luminescence of Eu3+ and green luminescence of Tb3+ indicate that an efficient energy transfer process exists within the hybrid systems.

Bing Yan

Papers

A novel dimeric europium complex of 5-amino-2-chlorobenzoic acid: Structure and photophysical properties

Sol–gel preparation and luminescence of RE 3 BO 6 : Dy 3+ (RE = La, Y, Gd) microparticles with hybrid precursors

Amorphous RE–Fe–B–Na colloidal nanoparticles: High temperature solution synthesis and magnetic properties

Eu3+/Sm3+ hybrids based with 8-hydroxybenz[de]anthracen-7-one organically modified mesoporous silica SBA-15/16

Novel luminescent rare earth hybrids covalently trapped through phthalic anhydride linkage