A Rhodium-Pentane Sigma-Alkane Complex: Characterization in the Solid State by Experimental and Computational Techniques

The pentane sigma-complex [Rh{Cy2P(CH2CH2)PCy2}((2):(2)-C5H12)][BAr4F] is synthesized by a solid/gas single-crystal to single-crystal transformation by addition of H-2 to a precursor 1,3-pentadiene complex. Characterization by low temperature single-crystal X-ray diffraction (150K) and SSNMR spectroscopy (158K) reveals coordination through two RhH-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 RhH-C interaction, the extended environment in the crystal lattice and a temperature-dependent pentane rearrangement implicated by the SSNMR data.