wileyonlinelibrary.comsuch as the mono-branched hexane isomer 3MP are usually still present and contribute to decrease the performance of the process. To overcome this drawback, there is a crucial need to search for alternative porous solids able to more selectively adsorb di-branched compounds such as the 22DMB from the mono-branched 3MP and linear nHEX.As a typical example, it was demonstrated that zeolite BETA could be used to upgrade the actual TIP processes by partially separating mono from di-branched hexane isomers in a dual layer pressure swing adsorption (PSA) bed with 5A zeolite, [ 3 ] leading to an enhancement of the RON number of the fi nal stream from 86 to 92, a value similar to the one obtained in the Hexsorb process of Axens. The achievement of higher upgrading thus calls for the design of more effi cient porous adsorbents. Metal organic frameworks (MOFs) are the latest class of crystalline porous solids. [ 6 ] These are built up from the linkage of inorganic sub-units and organic ligands, and constitute a versatile class of porous materials due to their large chemical and structural diversity, paving the way for their use in many societally relevant applications (gas storage, separation, catalysis, sensing, biomedicine, etc.) [ 7,8 ] In the fi eld of fl uid separation, it was shown for instance that MOFs could be of a great interest to separate propane from propylene, [ 9 ] xylene or alkane isomers, [ 10 ] carbon dioxide fromThe separation ability of branched alkane isomers ( n HEX, 3MP, 22DMB) of the fl exible and functionalized microporous iron(III) dicarboxylate MIL-53(Fe)-(CF 3 ) 2 solid is evaluated through a combination of breakthrough experiments (binary or ternary mixtures), adsorption isotherms, X-ray diffraction temperature analysis, quasi-elastic neutron scattering measurements and molecular dynamics simulations. A kinetically controlled molecular sieve separation between the di-branched isomer of hexane 22DMB from a mixture of paraffi ns is achieved. The reported total separation between mono-and di-branched alkanes which was neither predicted nor observed so far in any class of porous solids is spectacular and paves the way towards a potential unprecedented upgrading of the RON of gasoline.

Four novel zinc(II) metal-organic frameworks, {[Zn7(trz)6(1,3-bdc)4(H2O)2]·2H2O} n (1), {[Zn7(trz)6(hip)4(H2O)2]·8H2O} n (2), [Zn4(trz)4(Hnip)2(nip)] n (3), and [Zn5(trz)2(Hbtc)4(H2O)4] n (4) (Htrz = 1,2,4-triazole, 1,3-H2bdc = 1,3-benzenedicarboxylic acid, H2hip = 5-hydroxyisophthalic acid, H2nip = 5-nitroisophthalic acid, and H3btc = 1,3,5-benzenetricarboxylic acid), have been hydrothermally synthesized by reaction of Zn salt and Htrz with four different aromatic acids, respectively. Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by X-ray powder diffraction, elemental analyses, IR spectra, and TG analyses. The structures of compounds 1 and 2 are isostructural and feature the 3D structure containing multidimensional intersecting ring channels formed by the interconnection of 2D layers {[Zn7(trz)6]8+} n with 1,3-bdc (1) or hip (2). Compound 3 consists of {[Zn4(trz)4]4+} n layers with (4, 82) topology arranged in the −ABAB− stacking sequence, which are connected by nip pillars to generate a novel 3D open framework. Compound 4 is also in a 3D structure containing 2D layer motifs, which are further linked by btc ligands to complete the structure. There are two different building units [Zn2(trz)2]2+ and [ZnO6] within the 2D layers of 4. All of the compounds 1−4 exhibit the 3D pillared-layer structures. In the 2D layer motifs of these four compounds, trz ligands connect Zn ions in different coordination modes, which reflect the tendency of the trz ligand to bridge multiple metal sites, and the aromatic carboxylate ligands in compounds 1−4 serve as the pillar between the 2D layers, creating the 3D open frameworks. Moreover, these four compounds exhibit emission properties at room temperature in the solid state.

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