Synthesis and solid-state NMR structural characterization of polysiloxane-immobilized phosphine, phosphine-amine and phosphine-thiol ligand systems

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• 作者：Maciel ; G.E. ; Yang ; J.J. ; El-Nahhal ; I.M. ; Chuang ; I.-S.
• 刊名：Journal of Non-Crystalline Solids
• 出版年：1997
• 出版时间：June, 1997
• 年：1997
• 卷：212
• 期：2-3
• 页码：281-291
• 全文大小：800 K

文摘

Polysiloxane-immobilized phosphine ligand systems have been prepared by hydrolytic condensation of mixtures of Si(OEt)₄ and (R′O)₃Si(CH₂)_nPPh₂ (n = 2, R′= Me; n = 3, R′= Et). Polysiloxane-immobilized phosphine-amine and phosphine-thiol ligand systems have been prepared by hydrolytic condensation of mixtures of Si(OEt)₄, (R′O)₃Si(CH₂)_nPPh₂ (n = 2, R′ = Me; n = 3, R′ = Et) and (R′O)₃Si(CH₂)₃X (X = NH₂, R′ = Et; X = NHCH₂CH₂NH₂, R′ = Me) or (MeO)₃Si(CH₂)₃SH. In the polysiloxane-immobilized phosphine-amine and phosphine-thiol systems two types of ligand groups are introduced into the polysiloxane matrix during the sol-gel process. Solid-state,¹³C, ³¹P and i²⁹Si NMR spectroscopy was used to investigate the structures of the polysiloxane-immobilized ligand systems - e.g., to determine the presence of unhydrolyzed/uncondensed alkoxy groups, to determine the ratios of phosphine to phosphine oxide moieties, to determine details of the silicon-based backbone (relative populations of various types of RSi(−O−)₃ and Si(−O−)₄ moieties) and to establish domain homogeneity throughout a given material.