Laboratoire Catalyse et Spectrochimie, ENSICAEN, Université de Caen Basse Normandie, CNRS, 6 boulevard du Maréchal Juin, 14050 Caen, France.
Phys Chem Chem Phys. 2011 Jun 28;13(24):11748-56. doi: 10.1039/c1cp20502a. Epub 2011 May 19.
The present study illustrates the importance of the oxidation state of iron within the mesoporous iron trimesate [{Fe(3)O(H(2)O)(2)F(0.81)(OH)(0.19)}{C(6)H(3)(CO(2))(3)}(2)] denoted MIL-100(Fe) (MIL= Material from Institut Lavoisier) during adsorption of molecules that can interact with the accessible metal sites through π-back donation. Adsorption of CO has been first followed by FTIR spectroscopy to quantify the Lewis acid sites in the dehydrated Fe(III) sample, outgassed at 150 °C, and on the partially reduced Fe(II/III), outgassed at 250 °C. The exposure of MIL-100(Fe) to CO(2), propane, propene and propyne has then been studied by FTIR spectroscopy and microcalorimetry. It appears that π-back donating molecules are strongly adsorbed on reduced iron(II) sites despite the weaker Lewis acidity of cus Fe(2+) sites compared to that of Fe(3+) ones, as shown by pyridine adsorption.
本研究说明了在介孔铁三(间苯二甲酸根)[{Fe(3)O(H(2)O)(2)F(0.81)(OH)(0.19)}{C(6)H(3)(CO(2))(3)}(2)]（表示为 MIL-100(Fe)，MIL= Institut Lavoisier 材料）中，铁的氧化态在吸附可以通过π-back 供体与可及金属位相互作用的分子时的重要性。首先通过傅里叶变换红外光谱法（FTIR）跟踪 CO 的吸附，以定量测定在 150°C 脱气的脱水 Fe(III)样品中的路易斯酸位，以及在 250°C 脱气的部分还原 Fe(II/III)中的路易斯酸位。然后通过傅里叶变换红外光谱法和微量热法研究了 MIL-100(Fe)对 CO(2)、丙烷、丙烯和丙炔的吸附。尽管与 Fe(3+)位相比，cus Fe(2+)位的路易斯酸度较弱，但表明π-back 供体分子被强烈吸附在还原的 Fe(II)位上，这可以通过吡啶吸附来证明。
