Site-Isolated Pt-SBA15 Materials from Tris(tert-butoxy)siloxy Complexes of Pt(II) and Pt(IV)

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• 作者：Daniel A. Ruddy ; Jonggol Jarupatrakorn ; Robert M. Rioux ; Jeffrey T. Miller ; Meredith J. McMurdo ; Jennifer L. McBee ; Karl A. Tupper ; T. Don Tilley
• 刊名：Chemistry of Materials
• 出版年：2008
• 出版时间：October 28, 2008
• 年：2008
• 卷：20
• 期：20
• 页码：6517-6527
• 全文大小：258K
• 年卷期：v.20,no.20(October 28, 2008)
• ISSN：1520-5002

文摘

Two novel tris(tert-butoxy)siloxy complexes of Pt(II) and Pt(IV) were prepared in high yields, (cod)Pt[OSi(O^tBu)₃]₂ (1; 87%; cod = 1,5-cyclooctadiene) and Me₃Pt(tmeda)[OSi(O^tBu)₃] (2; 81%; tmeda = N,N,N′,N′-tetramethylethylenediamine). The structures of these compounds were determined by multinuclear NMR spectroscopy and by single-crystal X-ray analysis. The thermolytic chemistry of 1 and 2 in the solid state was studied by thermogravimetric analysis. The thermal decomposition of these complexes resulted in the formation of Pt metal, with the elimination of HOSi(O^tBu)₃. Precursors 1 and 2 react with the surface Si−OH groups of mesoporous SBA15 silica to generate surface-supported Pt centers. The coordination environments of the supported Pt centers in these new materials, termed Pt(II)SBA15 and Pt(IV)SBA15, were investigated using Fourier-transform infrared spectroscopy, X-ray absorption near-edge spectroscopy, and extended X-ray absorption fine structure analysis. These materials were also characterized using N₂ porosimetry, powder X-ray diffraction and transmission electron microscopy. Comparisons with the molecular precursors 1 and 2 revealed many similarities, and the results are indicative of isolated Pt(II) and Pt(IV) centers. In addition, isolated Pt centers proved to be robust in inert atmosphere to 150−200 °C, which is similar to the decomposition temperatures of 1 and 2.