The large-pore iron(III) carboxylate MIL-100(Fe) with a zeotype architecture has been isolated under hydrothermal conditions, its structure solved from synchrotron X-ray powder diffraction data, while Friedel-Crafts benzylation catalytic tests indicate a high activity and selectivity for MIL-100(Fe).
The recent interest in the synthesis of hybrid inorganic-organic solids gives a new dimension to the domain of porous compounds. [1][2][3][4] They offer significant new scientific and technological opportunities 5 by combining attractive features of both inorganic and organic moieties and lead to many potential applications in gas storage, 6,7 catalysis, 8,9 insertion, 10,11 magnetism, 12,13 optical devices, 14 etc. Most of them are prepared using functionalized organic ligand (phosphonates, carboxylates, sulfonates...) and many elements in the Periodic Table have been incorporated in these new framework materials exhibiting novel structures not seen in zeolite chemistry. The introduction of 3d transition metals within the skeleton provides new electronic properties. Among them, iron is an environmentally benign and cheap component with non-toxicity and redox properties. However, to the best of our knowledge, while some MOF materials have been reported to date with iron(II) or iron(III), [15][16][17][18][19][20] only two of them combine a permanent porosity and large pores. 21,22 We report here the successful synthesis and structure determination of MIL-100(Fe) (MIL: Materials of Institut Lavoisier), a new scarce example of an iron(III) carboxylate with a large accessible and permanent porosity.
This solid was isolated as a polycrystalline powder from a reaction mixture of composition 1.0 Fe 0 : 0.66 1,3,5-BTC : 2.0 HF : 1.2 HNO 3 : 280 H 2 O (1,3,5-BTC = benzene tricarboxylic or trimesic acid) that was held at 150 uC in a Teflon-lined autoclave for 6 days with a initial heating ramp of 12 h and a final cooling ramp of 24 h. The pH remains acidic (,1) throughout the synthesis. The light-orange solid product was recovered by filtration and washed with deionized water. A treatment in hot