| Abstract
| - A new aluminum trimesate Al12O(OH)18(H2O)3(Al2(OH)4)[btc]6·24H2O, denominated MIL-96, wassynthesized under mild hydrothermal conditions (210 °C, 24 h) in the presence of 1,3,5-benzenetricarboxylicacid (trimesic acid or H3btc) in water. Hexagonal crystals, allowing a single-crystal XRD analysis, are grownfrom a mixture of trimethyl 1,3,5-benzenetricarboxylate (Me3btc), HF, and TEOS. The MIL-96 structureexhibits a three-dimensional (3D) framework containing isolated trinuclear μ3-oxo-bridged aluminum clustersand infinite chains of AlO4(OH)2 and AlO2(OH)4 octahedra forming a honeycomb lattice based on18-membered rings. The two types of aluminum groups are connected to each other through the trimesatespecies, which induce corrugated chains of aluminum octahedra, linked via μ2-hydroxo bonds with thespecific -cis−cis−trans- sequence. The 3D framework of MIL-96 reveals three types of cages. Two ofthem, centered at the special positions 0 0 0 and 2/31/31/4, have estimated pore volumes of 417 and 635Å3, respectively, and encapsulate free water molecules. The third one has a smaller pore volume andcontains disordered aluminum octahedral species (Al(OH)6). The solid-state NMR characterization isconsistent with crystal structure and elemental and thermal analyses. The four aluminum crystallographicsites are resolved by means of 27Al 3QMAS technique. This product is able to sorb both carbon dioxideand methane at room temperature (4.4 mmol·g-1 for CO2 and 1.95 mmol·g-1 for CH4 at 10 bar) and hydrogenat 77 K (1.91 wt % under 3 bar).
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