C-C activation in the solid state in an organometallic σ-complex.

Herein is reported the synthesis, by a solid-state reaction from [Ir(NBD)(2)(P(i)Pr(3))][BAr(F)(4)], of the first example of a C-C σ-complex with iridium, [Ir(BINOR-S)(P(i)Pr(3))][BAr(F)(4)]. This compound is unique in that in the solid state it undergoes reversible activation of the C-C single bond that interacts with the metal center, establishing a temperature-dependent equilibrium between Ir(III) C-C σ/Ir(V) bis-alkyl complexes. This process has been interrogated by variable-temperature X-ray diffraction, NMR spectroscopy, and DFT calculations.