The preparation and X-ray crystal and molecular structure of (α,1,2-η-6-methylbenzyl) bis(triphenylphosphine)rhodium(I)

Reaction of RhCl(PPh₃)₃] with o-MeC₆H₄CH₂MgBr] affords high yields of the non-fluxional complex, Rh(CH₂C₆H₄Me)(PPh₃)₂] which has been shown crystallographically to contain a 1-3-η-benzyl group bound through the phenyl carbon atom that is not substituted with the methyl group. Crystals of this compound are triclinic, space group P$\text{1}$, with a = 10.561(6). b = 17.705(3), c = 10.934(4) Å, α = 80.69(3), β = 116.86(4), γ = 102.30(4)° and Z = 2. The structure was solved via the heavy-atom method and refined to R = 0.032 using 5379 diffractometer data with I > 1.56(I). Attempts to prepare π-bonded xylylene complexes from this compound by reaction with base have been unsuccessful, but protonation followed by recrystallisation from acetone gives Rh{(CH₃)₂CO}₂(PPh₃)₂]BF₄.