RuH₃(SiCl₂Me)(PPh₃)₃: A Trihydridosilylruthenium Complex with Three Nonclassical Ru−H···Si Interactions

The reaction of RuCl2(PPh3)3 with HSiMeCl2 in hexanes at 65 °C produced the trihydridosilylruthenium complex RuH3(SiMeCl2)(PPh3)3 (1). In the 1H{31P} NMR spectrum of 1, the ruthenium hydrides were observed at −9.76 ppm as a singlet with 29Si satellites (JSiH = 39.7 Hz), indicating the presence of nonclassical Ru···H···Si interactions. These nonclassical interactions were confirmed by a single-crystal X-ray diffraction study of 1. The silyl and phosphine groups occupy a tetrahedral arrangement around ruthenium, with the hydrides capping the faces defined by the silyl and two phosphines groups. Complex 1 exhibited a short Ru−Si bond (2.2760(4) Å) with three normal Ru−H distances (ca. 1.6 Å) and three long Si···H interactions (ca. 1.9 Å). The Ru−H and Si···H distances are consistent with interligand hypervalent interaction (IHI) theory in which Ru−H electron density is donated to Si−halogen σ* orbitals, giving rise to Ru−H···Si interactions. Differences between the three Si···H separations in the solid state reflect the asymmetry in the substituent pattern at silicon and are further reinforced by the extent to which the hydride ligands (and one chloride substituent) engage in weak hydrogen bonds with the ortho hydrogens of the phenyl groups.