Adsorptive separation is very important in industry. Generally, the process uses porous solid materials such as zeolites, activated carbons, or silica gels as adsorbents. With an ever increasing need for a more efficient, energy-saving, and environmentally benign procedure for gas separation, adsorbents with tailored structures and tunable surface properties must be found. Metal–organic frameworks (MOFs), constructed by metal-containing nodes connected by organic bridges, are such a new type of porous materials. They are promising candidates as adsorbents for gas separations due to their large surface areas, adjustable pore sizes and controllable properties, as well as acceptable thermal stability. This critical review starts with a brief introduction to gas separation and purification based on selective adsorption, followed by a review of gas selective adsorption in rigid and flexible MOFs. Based on possible mechanisms, selective adsorptions observed in MOFs are classified, and primary relationships between adsorption properties and framework features are analyzed. As a specific example of tailor-made MOFs, mesh-adjustable molecular sieves are emphasized and the underlying working mechanism elucidated. In addition to the experimental aspect, theoretical investigations from adsorption equilibrium to diffusion dynamics via molecular simulations are also briefly reviewed. Furthermore, gas separations in MOFs, including the molecular sieving effect, kinetic separation, the quantum sieving effect for H2/D2 separation, and MOF-based membranes are also summarized (227 references).

Selective gas adsorption and separation in metal–organic frameworks

1. Introduction 20642. Synthesis of Magnetic Nanoparticles 20662.1. Classical Synthesis by Coprecipitation 20662.2. Reactions in Constrained Environments 20682.3. Hydrothermal and High-TemperatureReactions20692.4. Sol-Gel Reactions 20702.5. Polyol Methods 20712.6. Flow Injection Syntheses 20712.7. Electrochemical Methods 20712.8. Aerosol/Vapor Methods 20712.9. Sonolysis 20723. Stabilization of Magnetic Particles 20723.1. Monomeric Stabilizers 20723.1.1. Carboxylates 20733.1.2. Phosphates 20733.2. Inorganic Materials 20733.2.1. Silica 20733.2.2. Gold 20743.3. Polymer Stabilizers 20743.3.1. Dextran 20743.3.2. Polyethylene Glycol (PEG) 20753.3.3. Polyvinyl Alcohol (PVA) 20753.3.4. Alginate 20753.3.5. Chitosan 20753.3.6. Other Polymers 20753.4. Other Strategies for Stabilization 20764. Methods of Vectorization of the Particles 20765. Structural and Physicochemical Characterization 20785.1. Size, Polydispersity, Shape, and SurfaceCharacterization20795.2. Structure of Ferro- or FerrimagneticNanoparticles20805.2.1. Ferro- and Ferrimagnetic Nanoparticles 20805.3. Use of Nanoparticles as Contrast Agents forMRI20825.3.1. High Anisotropy Model 20845.3.2. Small Crystal and Low Anisotropy EnergyLimit20855.3.3. Practical Interests of Magnetic NuclearRelaxation for the Characterization ofSuperparamagnetic Colloid20855.3.4. Relaxation of Agglomerated Systems 20856. Applications 20866.1. MRI: Cellular Labeling, Molecular Imaging(Inﬂammation, Apoptose, etc.)20866.2.

Magnetic Iron Oxide Nanoparticles: Synthesis, Stabilization, Vectorization, Physicochemical Characterizations, and Biological Applications

Ju Mei,†,‡,∥ Nelson L. C. Leung,†,‡,∥ Ryan T. K. Kwok,†,‡ Jacky W. Y. Lam,†,‡ and Ben Zhong Tang*,†,‡,§ †HKUST-Shenzhen Research Institute, Hi-Tech Park, Nanshan, Shenzhen 518057, China ‡Department of Chemistry, HKUST Jockey Club Institute for Advanced Study, Institute of Molecular Functional Materials, Division of Biomedical Engineering, State Key Laboratory of Molecular Neuroscience, Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China Guangdong Innovative Research Team, SCUT-HKUST Joint Research Laboratory, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China

Aggregation-Induced Emission: Together We Shine, United We Soar!

Metal–Organic Frameworks for Separations

It is possible to say that zeolites are the most widely used catalysts in industry They are crystalline microporous materials which have become extremely successful as catalysts for oil refining, petrochemistry, and organic synthesis in the production of fine and speciality chemicals, particularly when dealing with molecules having kinetic diameters below 10 A The reason for their success in catalysis is related to the following specific features of these materials:1 (1) They have very high surface area and adsorption capacity (2) The adsorption properties of the zeolites can be controlled, and they can be varied from hydrophobic to hydrophilic type materials (3) Active sites, such as acid sites for instance, can be generated in the framework and their strength and concentration can be tailored for a particular application (4) The sizes of their channels and cavities are in the range typical for many molecules of interest (5-12 A), and the strong electric fields2 existing in those micropores together with an electronic confinement of the guest molecules3 are responsible for a preactivation of the reactants (5) Their intricate channel structure allows the zeolites to present different types of shape selectivity, ie, product, reactant, and transition state, which can be used to direct a given catalytic reaction toward the desired product avoiding undesired side reactions (6) All of these properties of zeolites, which are of paramount importance in catalysis and make them attractive choices for the types of processes listed above, are ultimately dependent on the thermal and hydrothermal stability of these materials In the case of zeolites, they can be activated to produce very stable materials not just resistant to heat and steam but also to chemical attacks Avelino Corma Canos was born in Moncofar, Spain, in 1951 He studied chemistry at the Universidad de Valencia (1967−1973) and received his PhD at the Universidad Complutense de Madrid in 1976 He became director of the Instituto de Tecnologia Quimica (UPV-CSIC) at the Universidad Politecnica de Valencia in 1990 His current research field is zeolites as catalysts, covering aspects of synthesis, characterization and reactivity in acid−base and redox catalysis A Corma has written about 250 articles on these subjects in international journals, three books, and a number of reviews and book chapters He is a member of the Editorial Board of Zeolites, Catalysis Review Science and Engineering, Catalysis Letters, Applied Catalysis, Journal of Molecular Catalysis, Research Trends, CaTTech, and Journal of the Chemical Society, Chemical Communications A Corma is coauthor of 20 patents, five of them being for commercial applications He has been awarded with the Dupont Award on new materials (1995), and the Spanish National Award “Leonardo Torres Quevedo” on Technology Research (1996) 2373 Chem Rev 1997, 97, 2373−2419

From Microporous to Mesoporous Molecular-Sieve Materials and Their Use in Catalysis

The title compound, previously designated as JDF-2 [Gai-Boyes, Thomas, Wright, Jones, Natarajan, Chen & Xu (1992). J. Phys. Chem. 96, 8206-8209], is an aluminium phosphate (AlPO) with a three-dimensional framework structure consisting of three types of PO 4 tetrahedral unit linked to three crystallographically distinct Al atoms. One of the Al atoms is tetrahedrally coordinated (as AlO 4 ) while the remaining two have distorted trigonal bipyramidal coordination and are linked through a common O atom to form O 4 Al-OH-AlO 4 units. These units are relatively rare features in AlPO frameworks as the Al- and P-containing polyhedra are usually linked in a strictly alternating manner

A three‐dimensional framework aluminophosphate (CH3NH3)+[Al3P3O13H]−

A novel decanuclear Co(II) cluster, [Co10(Q)12(μ6-CO3)4]·2.5DMF (1) (Q = 8-hydroxyquinoline), has been synthesized under solvothermal conditions and characterized by powder XRD, TGA and IR spectroscopy. Single-crystal X-ray diffraction analysis shows that 1 represents a new type of decanuclear cobalt cluster with an approximate supertruncated tetrahedral shape coordinated with coexisted Q ligands and in situ formed μ6-bridging CO32− anions. Meanwhile, 1 is the largest aggregate in metal–Q coordination chemistry. Another distinguishing feature of 1 is the adamantane-like metallic skeleton with point symbol {63}2{6}3, which is observed in the polynuclear metal complexes for the first time. Furthermore, it is considered that the in situ formed CO32− anions have a crucial effect on the formation of the resultant unexpected polynuclear structures. The magnetic studies show that antiferromagnetic (AF) interactions exist within 1.

A novel decanuclear Co(II) cluster with adamantane-like metallic skeleton supported by 8-hydroxyquinoline and in situ formed CO32− anions

Three new iron aluminum phosphates |(C2H10N2)4|[Fe8 − xAlxFx(H2O)2 − x(PO4)8]·2H2O (χ = 1.64, 1.33, 0.80) with ACO-zeotype structures denoted as FeAPO-CJ66(a), FeAPO-CJ66(b), and FeAPO-CJ66(c), respectively, have been synthesized in the fluoride ion system. Their framework structures are made of double 4-ring (D4R) building units formed by the alternating connection of Fe(Al)O4F(O) trigonal bipyramids and PO4 tetrahedra, which possess 3D intersecting 8-ring channels running along the [001], [010], and [100] directions. Fluoride ions or water molecules reside in the center of D4Rs, and diprotonated ethylenediamine cations and water molecules are occluded in the free space of channels to stabilize the whole structure. Notably, the Al/Fe ratios in the frameworks can be effectively controlled from 1/3.9 to 1/5.0 to 1/9.0 by adjusting the amounts of phosphoric acid and hydrofluoric acid added to the initial reaction mixture. Mossbauer and magnetic measurements show that the Fe ions in the compounds are bivalen...

ACO-zeotype iron aluminum phosphates with variable Al/Fe ratios controlled by F⁻ ions.

A three-dimensional open-framework tin(II) phosphate [Sn4(PO4)3]-·0.5[C4N2H12]2+ has been synthesized under hydrothermal conditions using piperazine as the template. Its framework is built up from strictly alternating SnO3 and PO4 units that form eight-membered-ring channels along the [100] direction in which the diprotonated piperazine molecules are entrapped.

Ruren Xu

Papers

A three‐dimensional framework aluminophosphate (CH3NH3)+[Al3P3O13H]−

A novel decanuclear Co(II) cluster with adamantane-like metallic skeleton supported by 8-hydroxyquinoline and in situ formed CO32− anions

ACO-zeotype iron aluminum phosphates with variable Al/Fe ratios controlled by F⁻ ions.

Synthesis and structural characterization of a new open-framework tin(II) phosphate: [Sn4(PO4)3]-.0.5[C4N2H12]2+.

Synthesis and characterization of a new microporous aluminophosphate [Al2P2O8][OCH2CH2NH3] with an open-framework analogous to AlPO4-D