The molecular conformation of pentan-3-one studied in cholic acid pentan-3-one solvate

The crystal structure of cholic acid–pentan-3-one (1/1), C₅H₁₀O·C₂₄H₄₀O₅, has been determined in order to deduce the molecular conformation of the small volatile ketone. Data were collected at 100 K to a resolution of (sin θ)/λ = 0.91 Å⁻¹. The structure contains a hydrogen-bonded cholic acid host network, forming only van der Waals interactions with the guest pentan-3-one molecules. The ketone molecules are disordered on general positions, with two clearly identifiable conformations. The majority conformer exhibits approximate C₂ symmetry and is similar to that recently observed by microwave spectroscopy in the gas phase.