COMMUNICATIONSreaction inixture allixccd to stir at thih temperature. After 15 minutes, diethyl ether (10 m L) was condenscd onto the inixture. and I precipitated as acolorlesssolid. The liquid w a s decanted into the second iirin of the Schlenk vessel, the volatiles were pumped off undcr dynamic wxuum ;it --3O"C. and the solid was then allowed to bcarm slo~.ly to rooin tcmperature. 2. 3: After addition of the ether at -35 C a second phase was formed which was dccantrd into the second iirni of the reaction vessel. The workup of the residue was carried out as described for I .

Metathesis reactions are among the most important processes in organic synthesis. The decisive breakthrough in making these reactions practical for industrial purposes, which range from the synthesis of polymers to pharmaceuticals, came with the discovery of the reaction mechanism by Yves Chauvin and the targeted development of transition‐metal‐based metathesis catalysts by Richard Schrock and Robert Grubbs. The winners of the Chemistry Nobel Prize in 2005 present first‐hand accounts of these developments.

The synthesis of ruthenium nanoparticles, RuNPs from the organometallic complex (4-1,5-cyclooctadiene)(6-1,3,5-cyclooctatriene)ruthenium(0), Ru(COD)(COT) in various imidazolium derived ionic liquids, ILs: [RMIm][NTf2] (R = CnH2n + 1 with n = 2; 4; 6; 8; 10), and [R2Im][NTf2] (RBu) and [BMMIm][NTf2] has been performed, under 0.4 MPa of H2, at 25 °C or at 0 °C with or without stirring. A relationship between the size of IL non-polar domains calculated by molecular dynamics simulation and the RuNP size measured by TEM has been found, suggesting that the phenomenon of crystal growth is probably controlled by the local concentration of Ru(COD)(COT) and consequently is limited to the size of the non-polar domains. Moreover, the rigid 3D organization based on C2–Hanion bonding and chosen experimental conditions, could explain the non-aggregation of RuNPs