Heterometallic Hydride Complexes of Rare-Earth Metals and Ruthenium through C–H Bond Activation

The reaction of rare-earth monoalkyl complexes [Cp2Ln­(CH2SiMe3)­(thf)] (Cp = cyclopentadienyl;
Ln = Y, Lu) with the ruthenium hydride complex [HRu­(dmpe)­Cp] (dmpe
= bis­(dimethylphosphino)­ethane) gave the corresponding bimetallic
hydride complexes [Cp2Ln­(μ-H)­(μ-η1:η5-C5H4)­Ru­(dmpe)]
(Ln = Y (1a), Lu (1b)). One carbon atom
of the Ru-bound Cp ligand bridges to the Ln atom in these complexes.
The linkage is formed via a C–H bond activation step. The reaction
of 1a with diphenylacetylene led to the formation of
[Cp2Y­(μ-H)­{μ-(Ph)­CC­(Ph)­(C5H4)}­Ru­(dmpe)], which indicates that the Y–C σ-bond
is significantly more reactive than the Y–H–Ru bond.
The reaction of bis­(alkyl) complexes [Ln­(CH2SiMe3)2(OC6H3(tBu)2-2,6)­(thf)2] (Ln = Y, Lu, tBu = tert-butyl) with [HRu­(dmpe)­Cp]
gave the dimeric products [(OC6H3(tBu)2-2,6)­Ln­(μ-H)­(μ-η1:η5-C5H4)­{κ3C,P,P′-CH2(Me)­P­(CH2)2PMe2}­Ru]2 (Ln = Y, Lu) by double C–H bond activation. The complexes
were characterized by NMR spectroscopy, X-ray crystal structure analysis
(XRD), and elemental analysis.