The formation and molecular structure of (η⁵-C₅H₅)Rh(CO)[C(NMe)CH₂CH₂(NMe)]

A reaction between (η⁵-C₅H₅)Rh(CO)₂ and bis(1,3-dimethylimidazolindin-2-ylidene) in methylcyclohexane produces (η⁵-C₅H₅)Rh(CO)[C(NMe)CH₂CH₂(NMe)] in 53% yield. This mononuclear cyclopentadienylrhodium carbene complex was characterized by elemental analysis, ¹H NMR, ¹³C{¹H} NMR, IR, mass spectral, and single-crystal X-ray diffraction methods. The compound (η⁵-C₅H₅)Rh(CO)-[C(NMe)CH₂CH₂(NMe)] crystallizes in the monoclinic space group P2₁/n with a 9.053(3), b 10.256(4), c 12.696(5) Å, β 91.18(3)° and D_calc 1.66 g cm^-3 for Z = 4. The structure was refined by least-squares techniques to a final conventional R value of 0.045 using 1739 independent observed (I ≥ 3σ(I)) reflections. The overall structure is that of a two-legged piano stool. The RhC(η⁵) separations average 2.29(3) Å. The RhC and RhCO bond lengths are 1.994(7) and 1.795(9) Å, respectively.