Jae Yong Choi

Bio: Jae Yong Choi is an academic researcher from Seoul National University. The author has contributed to research in topics: Thermal stability & Aryne. The author has an hindex of 3, co-authored 3 publications receiving 4616 citations.

Exceptional chemical and thermal stability of zeolitic imidazolate frameworks

Abstract: Twelve zeolitic imidazolate frameworks (ZIFs; termed ZIF-1 to -12) have been synthesized as crystals by copolymerization of either Zn(II) (ZIF-1 to -4, -6 to -8, and -10 to -11) or Co(II) (ZIF-9 and -12) with imidazolate-type links. The ZIF crystal structures are based on the nets of seven distinct aluminosilicate zeolites: tetrahedral Si(Al) and the bridging O are replaced with transition metal ion and imidazolate link, respectively. In addition, one example of mixed-coordination imidazolate of Zn(II) and In(III) (ZIF-5) based on the garnet net is reported. Study of the gas adsorption and thermal and chemical stability of two prototypical members, ZIF-8 and -11, demonstrated their permanent porosity (Langmuir surface area = 1,810 m 2 /g), high thermal stability (up to 550°C), and remarkable chemical resistance to boiling alkaline water and organic solvents.

Microwave synthesis of a porous metal-organic framework, zinc terephthalate MOF-5

Abstract: Organic-inorganic porous hybrid materials are currently of great interest and importance for the novel coordination structure, relatively facile preparation, special properties and potential practical applications Recent studies have been focused on the design and synthesis of porous materials which possess a very low density, high surface area and specific functionality Among these materials, metal organic frameworks (MOFs), originally coined and intensively studied by Yaghi et al are crystalline and well-defined structures, consisting of metal ions or oxo-bridged metal clusters linked by organic carboxylates In particular, a series of MOF-5s have open metal frameworks with high Langmuir surface areas (1000-4500 m/g) and thermal stability These porous “organic” zeolites are mimicking the frame and properties of the zeolite, and thus many potential industrial applications arise from the promising properties of these high-surface materials The structural architecture of MOFs can be extended to the real zeotype frameworks by Ferey et al who showed the MTN type structure from chromium oxo cluster ion and terephthalate, very recently In general, MOFs can be synthesized by a slow diffusion method diffusion of amine into a solution containing metal salt and organic carboxylic acid for weeks or a solvothermal reaction technique for hours Recent literature, however, revealed that it is not easy to prepare MOF-5 with a high surface area by both methods Resulting MOF nanocrystalline materials and space group Fm-3m like MOF-5 materials had Langmuir surface areas of 727 and 572 m/g, respectively, but these figures are far below the reported value of 2900 m/g by Yaghi Furthermore, both groups noticed that their MOFs slowly tend to decompose in moisture and acid, thus this instability may limit their practical applications On the other hand, a microwave irradiation method has been studied in the syntheses of not only organic molecules but also inorganic materials More recently, microwaveassisted synthesis of inorganic materials requiring several days for their crystallization has attracted much attention This technique provides synthesis methods of porous materials with saving the reaction time within a few minutes and offering phase selectivity and facile morphology control Very recently, some of us recently reported that microwave technique can be well applied to the rapid synthesis as well as phase selective crystallization of porous hybrid solids including MIL-77, MIL-100 and MIL-101 Here we describe the first result on the microwave synthesis of MOF-5, Zn4(O)(BDC)3·guest molecules (BDC = 1,4benzenedicarboxylate) with a high surface area, as named MW MOF-5 (Microwave MOF-5) MW MOF-5 was synthesized in N,N'-diethylformamide (DEF) using microwave irradiation Equimolar amount of H2BDC (157 mg, 060 × 10−2 mmol) and zinc nitrate tetrahydrate (150 mg, 060 × 10−2mmol) in a DEF (06 mL) were place in a 10 mL tube The tube was sealed with a robber septum and placed in a microwave oven (Discover, CEM, maximum power of 300 W) The resulting mixture was heated at 95 C, held for 9 min and then cooled to room temperature The colorless crystalline materials (210 mg, 27% yield) were obtained by centrifuging, washing with N,N'-dimethylformamide (DMF, 3 × 5 mL) and drying briefly in the air The morphology of MW MOF-5 was studied by scanning electron microscopy (SEM) after gold deposition The SEM image shows three dimensional cube-like microcrystals with the length of 2-4 mm as illustrated in Figure 1 Its morphology was consistent with the previous result which was obtained from slow diffusion with addition of H2O2, even though SEM image of MOF-5 produced by H2O2 is not clear

Porous Chiral Metal Organic Carboxylate Frameworks with a Double-interwoven SrSi2 Topology: M3(TTCA)2·6DMF·7H2O (TTCA = triphenylenetricarboxylate; M = Zn2+, Cd2+)

Abstract: We have succeeded in assembling a new trigonal aryne ligand, triphenylene-2,6,10-tricarboxylic acid (H3TTCA) with metal ions to give M3(TTCA)2·6DMF·7H2O (M = Zn2+ and Cd2+) (DMF = N,N-dimethylforma...

The Chemistry and Applications of Metal-Organic Frameworks

Abstract: Crystalline metal-organic frameworks (MOFs) are formed by reticular synthesis, which creates strong bonds between inorganic and organic units. Careful selection of MOF constituents can yield crystals of ultrahigh porosity and high thermal and chemical stability. These characteristics allow the interior of MOFs to be chemically altered for use in gas separation, gas storage, and catalysis, among other applications. The precision commonly exercised in their chemical modification and the ability to expand their metrics without changing the underlying topology have not been achieved with other solids. MOFs whose chemical composition and shape of building units can be multiply varied within a particular structure already exist and may lead to materials that offer a synergistic combination of properties.

Carbon Dioxide Capture in Metal–Organic Frameworks

Abstract: Kenji Sumida, David L. Rogow, Jarad A. Mason, Thomas M. McDonald, Eric D. Bloch, Zoey R. Herm, Tae-Hyun Bae, Jeffrey R. Long

A new zirconium inorganic building brick forming metal organic frameworks with exceptional stability.

Abstract: Porous crystals are strategic materials with industrial applications within petrochemistry, catalysis, gas storage, and selective separation Their unique properties are based on the molecular-scale porous character However, a principal limitation of zeolites and similar oxide-based materials is the relatively small size of the pores, typically in the range of medium-sized molecules, limiting their use in pharmaceutical and fine chemical applications Metal organic frameworks (MOFs) provided a breakthrough in this respect New MOFs appear at a high and an increasing pace, but the appearances of new, stable inorganic building bricks are rare Here we present a new zirconium-based inorganic building brick that allows the synthesis of very high surface area MOFs with unprecedented stability The high stability is based on the combination of strong Zr−O bonds and the ability of the inner Zr6-cluster to rearrange reversibly upon removal or addition of μ3-OH groups, without any changes in the connecting carbox

Hydrogen storage in metal–organic frameworks

Abstract: New materials capable of storing hydrogen at high gravimetric and volumetric densities are required if hydrogen is to be widely employed as a clean alternative to hydrocarbon fuels in cars and other mobile applications. With exceptionally high surface areas and chemically-tunable structures, microporous metal–organic frameworks have recently emerged as some of the most promising candidate materials. In this critical review we provide an overview of the current status of hydrogen storage within such compounds. Particular emphasis is given to the relationships between structural features and the enthalpy of hydrogen adsorption, spectroscopic methods for probing framework–H2 interactions, and strategies for improving storage capacity (188 references).