Poly(Alumosiloxanes) as Matrixes for the Immobilization of Catalytically Active Ruthenium(II) Complexes

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• 作者：Ekkehard Lindner ; Andreas Jä ; ger ; Friedrich Auer ; Peter Wegner ; Hermann A. Mayer ; Andreas Benez ; Dorothea Adam ; and Erich Plies
• 刊名：Chemistry of Materials
• 出版年：1998
• 出版时间：January 1998
• 年：1998
• 卷：10
• 期：1
• 页码：217 - 225
• 全文大小：280K
• 年卷期：v.10,no.1(January 1998)
• ISSN：1520-5002

文摘

The trimethoxysilyl-(T)-functionalizedruthenium(II) complexescis-Cl(H)Ru(CO)(P~O)₃[2a(T⁰)₃,2b(T⁰)₃,and2c(T⁰)₃](T = T-type silicon atom, three oxygen neighbors, P~O=P-coordinated ether-phosphines with different spacer lengths) weresol-gel processed withdifferent silicon-containing precursors {tetraethoxysilane[Si(OEt)₄, Q⁰, Q= Q-type siliconatom, four oxygen neighbors], methyltrimethoxysilane[MeSi(OMe)₃, T⁰, T= T-type siliconatom, three oxygen neighbors], or dimethyldiethoxysilane[Me₂Si(OEt)₂,D⁰, D = D-typesilicon atom, two oxygen neighbors]} and aluminum 2-propanolate[Al(OiPr)₃]. All components are simultaneously polycondensed to result in thepoly(alumosiloxane)-bound ruthenium complexes[2(a,b,c)(Tⁿ)₃(Q^k,T^m,Dⁱ)_y(Al)_z][(Al) denotes(Al₂O₃)_1/2].From ³¹P and ¹³CCP/MAS NMR as well as IR spectroscopy it can be concluded that thecomplex fragmentcis-Cl(H)Ru(CO)(P~O)₃ ispreserved during the immobilization. The aluminum isincorporated as tetrahedrally coordinated AlO₄ units while6-fold-coordinated AlO₆ groups are builtin as interstitials. Stoichiometric formulas and structural modelsof the carrier matrixesare derived from ²⁷Al and ²⁹Sisolid-state NMR spectroscopy, including²⁷Al{¹H} REDORand ¹H-²⁷Al CP/MAS NMR techniques, aswell as energy-dispersive X-ray spectroscopy(EDX). The dynamic behavior of the various catalysts isinvestigated by 2D WISEspectroscopy and ³¹P CP/MAS NMR line widths. Theimmobilized complexes act ashydrogenation catalysts of n-butenal and are easy toseparate from the reaction mixture bysimple centrifugation.