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The synthesis of metal-organic frameworks with large three-dimensional channels that are permanently porous and chemically stable offers new opportunities in areas such as catalysis and separation. Two linkers (L1=4,4′,4′′,4′′′-([1,1′-biphenyl]-3,3′,5,5′-tetrayltetrakis(ethyne-2,1-diyl)) tetrabenzoic acid, L2=4,4′,4′′,4′′′-(pyrene-1,3,6,8-tetrayltetrakis(ethyne-2,1-diyl))tetrabenzoic acid) were used that have equivalent connectivity and dimensions but quite distinct torsional flexibility. With these, a solid solution material, [Zr6O4(OH)4(L1)2.6(L2)0.4]⋅(solvent) x, was formed that has three-dimensional crystalline permanent porosity with a surface area of over 4000 m2 g−1 that persists after immersion in water. These properties are not accessible for the isostructural phases made from the separate single linkers. [ABSTRACT FROM AUTHOR]

This paper reports the development of a prototype environmental gas cell, capable of allowing a single crystal to be exposed to different gas mixtures and/ or a vacuum whilst in situ on the single-crystal diffractometer. The design and application of the cell to the study of a single crystal in the presence of sulfur dioxide are described. [ABSTRACT FROM AUTHOR]

Abstract: A multi-technique investigation involving X-ray diffraction, solid-state NMR and first-principle calculations was carried out on the aluminophosphate material AlPO4-15. A synchrotron X-ray single-crystal diffraction study was carried out on the same sample as that used in solid-state NMR studies. The model from the single crystal study, together with a model from a literature high resolution study of the same material, was used as starting points for the first-principles calculations of the NMR parameters. This enabled the 31P and 27Al NMR spectra to be unambiguously assigned and all the NMR parameters calculated agreed well with the experimental spectra even without relaxing the X-ray derived structural models. [Copyright &y& Elsevier]

Describes the crystal structure of the metal-organic compound tricarbonyl(n[sup 6]-chlorobenzene)-chromium. Classic piano-stool structure; Domination of the extended structure by intermolecular π...H interactions and non-classical hydrogen bonds between carbonyl and arene moieties.

Crystal engineering of nanoporous structures has not yet exploited the heme motif so widely found in proteins. Here, we report that a derivative of iron phthalocyanine, a close analog of heme, forms millimeter-scale molecular crystals that contain large interconnected voids (8 cubic nanometers), defined by a cubic assembly of six phthalocyanines. Rapid ligand exchange is achieved within these phthalocyanine nanoporous crystals by single-crystal-to-single-crystal (SCSC) transformations. Differentiation of the binding sites, similar to that which occurs in hemoproteins, is achieved so that monodentate ligands add preferentially to the axial binding site within the cubic assembly, whereas bidentate ligands selectively bind to the opposite axial site to link the cubic assemblies. These bidentate ligands act as molecular wall ties to prevent the collapse of the molecular crystal during the removal of solvent. The resulting crystals possess high surface areas (850 to 1000 square meters per gram) and bind N2 at the equivalent of the heme distal site through a SCSC process characterized by x-ray crystallography. [ABSTRACT FROM AUTHOR]

Abstract: The calcium trimellitate, Ca(H2O)[(O2C)2–C6H3–CO2H], was hydrothermally synthesized from a mixture of calcium hydroxide, 1,2,4-benzenetricarboxylic (or trimellitic) acid and water at 180°C for 24h (under autogenous pressure). Its crystal structure has been determined by single-crystal X-ray diffraction analysis using synchrotron radiation (station 9.8, SRS Daresbury, UK). It consists of infinite chains of calcium bicapped trigonal prismatic polyhedra connected to each other through the 1,2,4-benzenetricarboxylate ligand. The eight-fold coordinated calcium cation is bonded to one terminal water molecule, two carboxylate groups with a chelating conformation and three carboxylate groups in a monodentating mode. One of the monodentate carboxylate is terminal with the occurrence of protonated C–OH bonding. Triclinic space group P-1 with a =6.9073(4)Å, b =6.9917(4)Å, c =10.3561(6)Å, α =87.178(1)°, β =83.233(1)°, γ =69.576(1)°, V =465.41(5)Å3. [Copyright &y& Elsevier]

The reactions of the fluorovinyl-substituted phosphines PPh2(CF＝CF2) and PPh2(CCl＝CF2), with K2PtX4 (X=Br, I) have been investigated. The resulting complexes have been characterized by a combination of 19F and 31P{1H} NMR, IR and Raman spectroscopy. The reactions of these phosphines with K2PtBr4 yield the monomeric complexes cis-[PtBr2{PPh2(CF＝CF2)}2] (1) and trans-[PtBr2{PPh2(CCl＝CF2)}2] (2), respectively, whilst the reactions with K2PtI4 yield both the monomeric species trans-[PtI2{PPh2(CX=CF2)}2], {X=F (3), Cl (4)}, and the dimeric species [PtI(μ-I){PPh2(CX=CF2)}]2, {X=F (5), Cl (6)}. The dimers 5 and 6 represent the first crystallographically characterised platinum(II) iodide-bridged phosphine complexes, and both adopt the symmetric-trans structure. [Copyright &y& Elsevier]