Tuning the selectivity of ruthenium nanoscale catalysts with functionalised ionic liquids: Hydrogenation of nitriles

Ruthenium nanoparticles prepared in nitrile-functionalised ionic liquids (ILs) display unusual selectivities toward the hydrogenation of nitrile containing aromatic compounds. In particular, a selective catalytic hydrogenative coupling of nitriles was observed. In this transformation, nitrile groups are exclusively hydrogenated in the presence of arenes, which are typically hydrogenated by ruthenium nanoparticles in non-functionalised ILs. The catalyst material was characterised by means of TEM and EDS analysis. Furthermore, molecular species formed during the catalytic process were characterised by MS-analysis of the gaseous phase and the ionic liquid phase by ESI/MS Q-TOF.

Graphical abstractNitrile groups are exclusively hydrogenated in the presence of arenes by ruthenium nanoparticles (2.2 ± 0.5 nm) prepared in nitrile-functionalised ionic liquids. On opposition, ruthenium nanoparticles in non-functionalised imidazolium ionic liquids promote preferentially the hydrogenation of the aromatic rings. The substrates bearing a nitrile group coordinated preferentially to the metal surface via the nitrile group rather than the arene moiety.Figure optionsDownload full-size imageDownload as PowerPoint slide