Propane/propene separation by cryogenic distillation is one of the most energy and cost intensive industrial processes. Adsorptive separation is a more energy-efficient alternative. Three isostructural zinc imidazolate zeolitic framework materials are found, for the first time, to be very promising in the separation of propene and propane based on their different diffusion rates. Fine-tuning of the pore opening size is critical for this type of separation.

Sensors and sensitivity: A highly luminescent microporous metal-organic framework, [Zn(2)(bpdc)(2)(bpee)] (bpdc = 4,4'-biphenyldicarboxylate; bpee = 1,2-bipyridylethene), is capable of very fast and reversible detection of the vapors of the nitroaromatic explosive 2,4-dinitrotoluene and the plastic explosive taggant 2,3-dimethyl-2,3-dinitrobutane, through redox fluorescence quenching with unprecedented sensitivity (see spectra).

Ein hoch empfindlicher Sensor: Mit dem intensiv lumineszierenden mikroporösen Metall‐organischen Gerüst [Zn2(bpdc)2(bpee)] (bpdc=4,4′‐Biphenyldicarboxylat; bpee=1,2‐Bipyridylethen) lassen sich Dämpfe des Nitrosprengstoffs 2,4‐Dinitrotoluol und von 2,3‐Dimethyl‐2,3‐dinitrobutan, das Plastiksprengstoff als Markierung zugemischt wird, durch Redox‐Fluoreszenzlöschung sehr schnell, reversibel und mit unerreichter Empfindlichkeit nachweisen (siehe Spektren).

Microporous materials [M3(HCOO)6] · DMF (M = Mn, Co, Ni) were synthesized solvothermally and structurally characterized by single crystal and powder X‐ray diffraction methods. The metal network exhibits diamondoid connectivity and the overall framework gives rise to zigzag channels along the b axis where guest dimethylformamide molecules reside. The effective pore size of these channels is ∼5–6 Å. The materials feature high thermal stability and permanent porosity with relatively small pore diameters which are attributed to the extensive strong dative bonding between the metal centers and formate molecules. The title compounds exhibit interesting multi‐fold gas adsorption and magnetic properties. The adsorption study of a series of alcohols, aromatics, and linear hydrocarbons revealed strong control of the adsorbent channel structures on their adsorption capacity and selectivity. The study also indicated possibility of using these materials for separation of close boiling chemicals (e.g., ethylbenzene and p‐xylene) via pressure swing adsorption (PSA) process and molecules with different diffusion parameters via kinetic‐based process. Three‐dimensional spontaneous magnetic ordering was found in all three network structures investigated and at ground states they behave somewhat like soft magnets.

Infrared (IR) absorption spectroscopy measurements, performed at 300 K and high pressures (27-55 bar) on several prototypes of metal organic framework (MOF) materials, reveal that the MOF ligands are weakly perturbed upon incorporation of guest molecules and that the molecular hydrogen (H(2)) stretch mode is red-shifted (30-40 cm(-1)) from its unperturbed value (4155 cm(-1) for ortho H(2)). For MOFs of the form M(bdc)(ted)(0.5) (bdc = 1,4-benzenedicarboxylate; ted = triethylenediamine), H(2) molecules interact with the organic ligands instead of the saturated metal centers located at the corners of the unit cell. First-principles van der Waals density functional calculations identify the binding sites and further show that the induced dipole associated with the trapped H(2) depends sensitively on these sites. For M(bdc)(ted)(0.5) systems, the strongest dipole moment is of the site that is in the corner of the unit cell and is dominated by the interaction with the benzene ligand and not by the metal center. For MOFs of the M(3)[HCOO](6) type with relatively short ligands (i.e., formate) and 1-D pore structures, there is a weak dependence of H(2) vibrational frequency on the cations, due to a small change in the unit cell dimension. Furthermore, translational states of approximately +/-100 cm(-1) are clearly observed as side bands on the H(2) stretch mode in these 1-D channels interconnected by very small apertures. The H(2) stretch IR integrated areas in all the MOFs considered in this work increase linearly with H(2) pressure, consistent with isotherm measurements performed in similar conditions. However, the IR intensity varies substantially, depending on the number of benzene rings interacting with the H(2) molecules. Finally, there is no correlation between H(2) binding energies (determined by isotherm measurements) and the magnitude of the H(2) stretch shift, indicating that IR shifts are dominated by the environment (organic ligand, metal center, and structure) rather than the strength of the interaction. These results highlight the relevance of IR spectroscopy to determine the type and arrangement of ligands in the structure of MOFs.