There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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.

The Chemistry and Applications of Metal-Organic Frameworks

J. Appl. Cryst.の発刊に際して

The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures, compositions and properties. In particular, highly porous frameworks held together by strong metal-oxygen-carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.

/pdf/reticular-synthesis-and-the-design-of-new-materials-lazbx7tdux.pdf

Reticular synthesis and the design of new materials

The title copper(I) compound has been isolated, whose X-ray crystallographic structure shows a rare polymerization mode in which the tetranuclear copper units, composed of three- and two-coordinate copper(I) atoms, are linked by pyrazines. This gives a cyclic voltammogram and a chrage transfer band characteristic of the polymeric structure in the solid state.

Tetranuclear Copper(I)-Based Infinite One-Dimentional Chain Complex. Synthesis and X-Ray Crystal Structure of {[Cu2(μ-3-methylpyridazine)2(μ-pyrazine)3](ClO4)2}∞

We investigated the encapsulation of bioactive molecules such as L-glutamic acid (Glu) into a series of porous coordination polymers (PCPs) based on aluminum hydroxy dicarboxylates [Al(OH)(L)]n (L = dicarboxylate ligand) and the molecular release therefrom. The use of 2,6-naphthalene dicarboxylate (2,6-ndc), 1,4-benzene dicarboxylate (1,4-bdc) and 1,4-naphthalene dicarboxylate (1,4-ndc) as ligands allows us to systematically tune the pore size and the flexibility of frameworks while keeping the same topology and thus to investigate the effect of those parameters upon both adsorption and release of Glu. We revealed the impact of zwitterionic nature of Glu upon loading efficiency; optimal loading pH was shown to be that for which Glu bears both positive and negative charges. Whereas the loading capacity of PCPs is governed by the pore size ([Al(OH)(2,6-ndc)]n > [Al(OH)(1,4-bdc)]n > [Al(OH)(1,4-ndc)]n), the adsorption isotherm clearly revealed that small or flexible pores induce the stronger Glu–PCP interaction. The release experiments of Glu from PCPs in a physiological media (pH = 7.4, 37 °C) demonstrated the exceptional stabilization of Glu within [Al(OH)(1,4-bdc)]n, compared to those within the other frameworks; whereas the rigid frameworks of [Al(OH)(2,6-ndc)]n and [Al(OH)(1,4-ndc)]n spontaneously released almost the entire Glu contents within 10 h, 70% of Glu loaded within [Al(OH)(1,4-bdc)]n still remained therein over 24 h. Interestingly, the burst release of Glu was triggered by increasing temperature up to 80 °C, at which the framework changed its structure from a closed phase to the open phase.

L-Glutamic acid release from a series of aluminum-based isoreticular porous coordination polymers

等原子価ドーピングを施したBaFe 2 (As 1-x P x )における異常な超伝導と反強磁性量子臨界挙動

Design of Porous Coordination Polymers/Metal–Organic Frameworks: Past, Present and Future

The present invention relates to a substrate having particles of Metal Organic Framework (MOF) fixed thereto, said particles being partially embedded into a surface of the substrate.

Susumu Kitagawa

Papers

Tetranuclear Copper(I)-Based Infinite One-Dimentional Chain Complex. Synthesis and X-Ray Crystal Structure of {[Cu2(μ-3-methylpyridazine)2(μ-pyrazine)3](ClO4)2}∞

L-Glutamic acid release from a series of aluminum-based isoreticular porous coordination polymers

等原子価ドーピングを施したBaFe 2 (As 1-x P x )における異常な超伝導と反強磁性量子臨界挙動

Design of Porous Coordination Polymers/Metal–Organic Frameworks: Past, Present and Future

Metal organic frameworks