C-H and Si-H Activation Reactions at Ru/Ga Complexes: A Combined Experimental and Theoretical Case Study on the Ru-Ga Bond

Maximilian Muhr (1) , Raphael Bühler (1) , Hao Liang (2) , Jonas Gilch (1) , Christian Jandl (1) , Samia Kahlal (2) , Jean-Yves Saillard (2) , Christian Gemel (1) , Roland A Fischer (1)

1 TUM - Technische Universität Munchen - Technical University Munich - Université Technique de Munich
2 ISCR - Institut des Sciences Chimiques de Rennes

Treatment of  [Ru(COD)(MeAllyl) 2 ] and [Ru(COD)(COT)]  with GaCp* under hydrogenolytic conditions leads to reactive intermediates which activate Si-H or C-H bonds, respectively. The product complexes [Ru(GaCp*) 3 (SiEt 3 )H 3 ] ( 1 ) and [Ru(GaCp*) 3 (C 7 H 7 )H 3 ] ( 2 ) are formed with HSiEt 3 or with toluene as the solvent, respectively. While  1  was isolated and fully characterized by NMR, MS, IR and SC-XRD,  2  was too labile to be isolated and was observed and characterized  in-situ  by using mass spectrometry, including labelling experiments for the unambiguous assignment of the elemental composition. The structural assignment was confirmed by DFT computations. The relative energies of the four isomers possible upon toluene activation at the  ortho -,  meta -,  para - and CH 3 -positions have been determined and point  to aromatic C-H activation. The Ru-Ga bond was analyzed by EDA and QTAIM and compared to the Ru-P bond in the analogue phosphine compound. Bonding analyses indicate that the Ru-GaCp* bond is weaker than the Ru-PR 3  bond.

Mots clés: Bond Activation; Cluster intermediates; Density functional calculations; Intermetallic compounds; Mass spectrometry

Domaines: Chimie

Maximilian Muhr, Raphael Bühler, Hao Liang, Jonas Gilch, Christian Jandl, et al.. C-H and Si-H Activation Reactions at Ru/Ga Complexes: A Combined Experimental and Theoretical Case Study on the Ru-Ga Bond. Chemistry - A European Journal, 2022, 28 (54), pp.e202200887. ⟨10.1002/chem.202200887⟩. ⟨hal-03719272⟩