Cost-effective 17O enrichment of metal–organic frameworks enables the composition and disorder in mixed-metal materials to be determined using NMR spectroscopy.

Single-crystal X-ray diffraction with synchrotron radiation enabled the structure of microcrystalline SSZ-23 (see drawing on the right), the first zeolite with channels bounded by seven- and nine-membered rings, to be solved.

Aluminum I 2100Ionic Liquids and Eutectic Mixtures as Solvent and Template in Synthesis of Zeolite Analogues. -The synthesis of different aluminophosphate zeolite analogues using 1-ethyl-3-methyl imidazolium bromide or a choline chloride/urea eutectic mixture as both solvent and template is demonstrated. Because of the vanishingly low vapor pressure of ionic liquids, synthesis takes place at ambient pressure, eliminating safety concerns associated with high hydrothermal pressures. The ionic liquid can also be recycled for further use. The structures of (II) (triclinic, space group P1; novel structure type), (III) (orthorhombic, Pna21, Z = 4; novel zeotype), (IV) (orthorhombic, Ibm2; AlPO-11 type), and (V) (triclinic, P1; AlPO-34 type) are determined by single crystal XRD. -(COOPER, E. R.; ANDREWS, C. D.; WHEATLEY, P. S.; WEBB, P. B.; WORMALD, P.; MORRIS, R. E.; Nature (London, UK) 430 (2004) 7003,

Highly porous metal-organic frameworks (MOFs), which have undergone exciting developments over the past few decades, show promise for a wide range of applications. However, many studies indicate that they suffer from significant stability issues, especially with respect to their interactions with water, which severely limits their practical potential. Here we demonstrate how the presence of 'sacrificial' bonds in the coordination environment of its metal centres (referred to as hemilability) endows a dehydrated copper-based MOF with good hydrolytic stability. On exposure to water, in contrast to the indiscriminate breaking of coordination bonds that typically results in structure degradation, it is non-structural weak interactions between the MOF's copper paddlewheel clusters that are broken and the framework recovers its as-synthesized, hydrated structure. This MOF retained its structural integrity even after contact with water for one year, whereas HKUST-1, a compositionally similar material that lacks these sacrificial bonds, loses its crystallinity in less than a day under the same conditions.

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Single-crystal X-ray diffraction studies carried out at a synchrotron radiation source have allowed the structure solution and location of fluoride ions inside as-made pure silica zeolites with the IFR and STF framework structures. The local environment of the fluoride has been identified, and unusual ordering of the fluoride ions has been discovered in both cases. The details of the crystal structures are used to suggest structural features that are important in determining the ordering of fluoride ions in zeolites. A mechanism for how the fluoride ordering occurs is suggested for IFR and STF based on the local structure of small cages that make up these zeolites, and the implications for the mechanism of crystal growth are discussed.

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Die Speicherung von Gasen in Festkörpern gewinnt zunehmend an Bedeutung. Anwendungen und Perspektiven dieser Technologie reichen von der Energiewirtschaft und dem Umweltschutz bis hin zur Biologie und Medizin. Hoch poröse Festkörper wie Zeolithe, Kohlenstoffmaterialien, Polymere und metall‐organische Netzwerke sind mit breit variierbaren chemischen Zusammensetzungen und Strukturen zugänglich. In diesen Architekturen können zahlreiche Gase adsorbiert und gespeichert werden – allen voran Wasserstoff, aber auch Methan, Stickstoffmonoxid und Kohlendioxid. Allerdings ist die Entwicklung von Materialien mit hinreichender Adsorptionskapazität und Lebensdauer, kontrollierbarem Gasfluss und effizienter Wiederbeladung nicht trivial. Das unterschiedliche chemische Verhalten der einzelnen Gase macht es erforderlich, die Eigenschaften des porösen Materials sorgfältig auf die gewünschte Anwendung abzustimmen.