Para-hydrogen induced polarization in homogeneous phase—an example of how ionic liquids affect homogenization and thus activation of catalysts

文献情報

出版日 2009-08-13

DOI 10.1039/B908198D

インパクトファクター 3.676

著者

Torsten Gutmann, Martin Sellin, Hergen Breitzke, Annegret Stark, Gerd Buntkowsky

原文を見る

要旨

Para-hydrogen induced polarization (PHIP) is observed in an organic solvent-free homogeneous catalyst/substrate system using ionic liquids. The hydrogenation reactions are performed employing a Rh-catalyst/ionic liquid system without further organic solvents. The PHIP phenomenon is demonstrated for the ethyl acrylate system. Small amounts of ionic liquids (ILs) containing weakly coordinating anions such as [Tf2N]− act as homogenizing cosolvents for the catalyst in ethyl acrylate, leading to a dramatic activation of the catalytic process and a high PHIP signal enhancement. The achieved enhancement depends strongly on the viscosity of the ethyl acrylate/IL mixture. Furthermore, by deliberate choice of the IL constituents it was possible to design a model system exhibiting both sufficient catalyst solubility and biphasic liquid–liquid behavior. This shows that in ionic liquids PHIP enhancements followed by a fast quantitative removal of the para-hydrogenated product from the catalyst phase is in principle possible. The possible PHIP enhancement factors will depend strongly on the design of a suitable hydrogenation reactor.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

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