A Hydrogen Clathrate Hydrate with Cyclohexanone: Structure and Stability

High-resolution neutron diffraction measurements have been used to confirm the crystal structure of the binary clathrate hydrate of cyclohexanone and hydrogen, making cyclohexanone one of the largest known sII hydrate formers. The position, orientation, and occupancy of the guest molecules within the hydrate cavities have been determined. Because cyclohexanone falls into the class of large sII forming molecules that require a second guest for stability, the role of hydrogen in hydrate stability is further elucidated. From these results, we suggest that the stabilization behavior of hydrogen is analogous to that of other more common hydrate forming molecules and suggest that hydrogen has the potential to stabilize other clathrate structures with greater hydrogen storage capacity.