Probing Reactive Platinum Sites in UiO-67 Zirconium Metal鈥揙rganic Frameworks

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• 作者：Sigurd 脴ien ; Giovanni Agostini ; Stian Svelle ; Elisa Borfecchia ; Kirill A. Lomachenko ; Lorenzo Mino ; Erik Gallo ; Silvia Bordiga ; Unni Olsbye ; Karl Petter Lillerud ; Carlo Lamberti
• 刊名：Chemistry of Materials
• 出版年：2015
• 出版时间：February 10, 2015
• 年：2015
• 卷：27
• 期：3
• 页码：1042-1056
• 全文大小：840K
• ISSN：1520-5002

文摘

We present three methods of the synthesis of zirconium metal鈥搊rganic framework UiO-67 functionalized with platinum bipyridine coordination complexes (bpydcPt^IICl₂ and bpydcPt^IVCl₄) acting as linkers in the MOF framework. These Pt complexes can be reduced to bpydcPt⁰ under flow of H₂ gas in the 600鈥?00 K range, as probed by a sophisticated parametric refinement of in situ EXAFS data. IR spectroscopy testifies the high coordinative unsaturation of the reduced centers, able to form bpydcPt⁰(CO)₂ dicarbonyl complexes upon CO adsorption. The large pore size of UiO-67 allows for ligand exchange between 2 Cl^{鈥?/sup> and even bulky ligands such as toluene-3,4-dithiol. Framework bpydcPtIICl₂ complexes can also be oxidized at room temperature to bpydcPtIVBr₄ through oxidative addition of liquid Br₂. XANES spectroscopy was used to monitor the changes in the Pt oxidation state along the observed reactions. Platinum bipyridine-functionalized UiO-67-Pt displays the same exceptional stability as the parent material as testified on both long and local range by in situ XRPD and Pt L₃-edge EXAFS data.}