A Rhodium-pentane sigma-alkane complex: Characterization in the solid-state by experimental and computational techniques

The pentane σ-complex [Rh{Cy2P(CH2CH2)PCy2}(η2:η2-C5H12)][BArF4] is synthesized by a solid/gas single-crystal to single-crystal transformation by addition of H2 to a precursor 1,3-pentadiene complex. Characterization by low temperature single-crystal X-ray diffraction (150 K) and SSNMR spectroscopy (158 K) reveals coordination through two Rh⋅⋅⋅H−C interactions in the 2,4-positions of the linear alkane. Periodic DFT calculations and molecular dynamics on the structure in the solid state provide insight into the experimentally observed Rh⋅⋅⋅H−C interaction, the extended environment in the crystal lattice and a temperature-dependent pentane rearrangement implicated by the SSNMR data.