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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

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

A critical review of the emerging field of MOF-based catalysis is presented. Discussed are examples of: (a) opportunistic catalysis with metal nodes, (b) designed catalysis with framework nodes, (c) catalysis by homogeneous catalysts incorporated as framework struts, (d) catalysis by MOF-encapsulated molecular species, (e) catalysis by metal-free organic struts or cavity modifiers, and (f) catalysis by MOF-encapsulated clusters (66 references).

Metal–organic framework materials as catalysts

Interaction of (Et4N)2WS4 with HX (X=Cl, Br) in methylene chloride has been studied. Conditions have been found which lead to the formation of tetraethylammonium salts containing W4S122−, W3S92−, W2S4X42−, W2S3Br82− and W2S4X82−. Mutual transformations between binuclear thiohalide complexes of tungsten have been studied. Complex W2S3Br6·2CH3CN has been obtained by interacting Br2 with (Et4N)2W2S4Br4 in acetonitrile. Boiling of (Et4N)2W2S3Br8 with elemental sulfur in acetonitrile produced complex (Et4N)2W2S4Br8 whose structure was established by X-ray structural analysis.

Synthesis and Characterization of Binuclear Thiohalide Complexes of Tungsten(V).

Preparation, Structure, and Reactivity of Ge‐Containing Heterometallic Cube Derivatives of [M3E4(H2O)9]4+ (M: Mo, W; E: S, Se).

New polyoxometalates are synthesized in which the polyoxometalate standard building block {W3O4}10+ is replaced by topologically similar chalcogenide cluster fragments {Mo3S4}4+, {Mo3S2O2}4+, and {Mo3CuS4}5+.

Vladimir P. Fedin

Papers

Synthesis and Characterization of Binuclear Thiohalide Complexes of Tungsten(V).

Preparation, Structure, and Reactivity of Ge‐Containing Heterometallic Cube Derivatives of [M3E4(H2O)9]4+ (M: Mo, W; E: S, Se).

New Cluster—Polyoxometalate Hybrids Derived from the Incorporation of {Mo3S4} and {Mo3CuS4} Units into {EW15} Cores (E: AsIII, SbIII, TeIV).

Triangular W3S4+ 7 and W3S4+ 4 Complexes.

Metal-Organic Frameworks for Adsorption-Based Separation of Hydrocarbons