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.

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Reticular synthesis and the design of new materials

A new dithio ligand containing sulfhydryl and thioamido group, N-phenyl-β-mercapto-thiocinnamamide, was prepared and its properties were studied. Although the nuclear magnetic resonance (NMR) spectrum did not show the SH signal, the v(SH) was observed in the infrared (IR) spectrum. The mass spectrum and the molecular weight estimation revealed that the ligand has a monomer structure. The λmax (e) in EtOH are as follows ; 347 nm (15600), 265 and 229 sh. The pKa value in 10% EtOH aqueous solution was determined spectrophotometrically to be 3.16±0.03. The low pKa value was supposed to be an existence of a strong hydrogen bond.

Preparation of a New Dithioligand

Organization at the atomic scale of metal cations by connecting them with organic linkers leads to the construction of hybrid crystalline microporous frameworks, also known as porous coordination polymers (PCPs) Owing to their high loading capacity and their chemical composition versatility, PCPs are attractive for applications such as gas storage, catalysis, sensing, proton conduction, or adsorptive separation Beside the conventional research that aims at designing PCP crystal characteristics at the molecular scale, recent research efforts focused on the modulation of the crystal size and shape and on the synthesis of polycrystalline macrostructures with well-defined morphologies Indeed, a major challenge today is to develop strategies that allow the integration of PCPs into readily applicable devices, which fully exploit the attributes of these promising materials The highly reactive surfaces of PCPs (composed of partially coordinated organic ligands or uncoordinated metal centers), the possible modulation of the coordination equilibrium at the crystal surface, and the large number of PCP frameworks available (implying a large range of possible synthesis conditions) make their synthesis compatible with a wide range of physicochemical and mechanical microfabrication methods Syntheses of uniform PCP nanocrystal suspensions, crystal assemblies in the form of membranes, pattern surfaces, hollow spheres, coatings, or multiporous architectures were therefore reported This chapter aims to review the most promising strategies reported so far to synthesize PCP nanocrystals and PCP-based macrostructures and composites


Keywords:

porous coordination polymer;
nanoscale;
nanocrystals;
macrostructures;
processing;
assemblies;
heterogeneous crystallization;
composites

Metal‐Organic Frameworks: Coordination Polymer Nanoparticles and Macrostructures

Protein engineering: Construction of Robust Bio‐nanotubes using the Controlled Self‐Assembly of Component Proteins of Bacteriophage T4 (Small 17/2010)

Entangled porous coordination frameworks, wherein two or more distinct frameworks are catenated over an entire crystal, are known to demonstrate unique structural flexibilities in response to the a...

Control over Flexibility of Entangled Porous Coordination Frameworks by Molecular and Mesoscopic Chemistries

Isomers of [Ru2III,III(3,5-DTBCat)4]2− (3,5-DTBCat2− = 3,5-di-tert-butylcatecholate) were successfully characterized. It is found that the isomerization from the kinetically stable cis,cis form to ...

Susumu Kitagawa

Papers

Preparation of a New Dithioligand

Metal‐Organic Frameworks: Coordination Polymer Nanoparticles and Macrostructures

Protein engineering: Construction of Robust Bio‐nanotubes using the Controlled Self‐Assembly of Component Proteins of Bacteriophage T4 (Small 17/2010)

Control over Flexibility of Entangled Porous Coordination Frameworks by Molecular and Mesoscopic Chemistries

Effect of countercations on the structural isomerization of a dianionic diruthenium complex with a ligand-unsupported Ru-Ru bond