Phase Transition of a StructureII Cubic Clathrate Hydrate to a Tetragonal Form

Satoshi Takeya, Hiroshi Fujihisa, Hiroshi Yamawaki, Yoshito Gotoh, Ryo Ohmura, Saman Alavi, John A. Ripmeester

Research output: Contribution to journalArticle

8 Citations (Scopus)


The crystal structure and phase transition of cubic structureII (sII) binary clathrate hydrates of methane (CH4) and propanol are reported from powder X-ray diffraction measurements. The deformation of host water cages at the cubic-tetragonal phase transition of 2-propanol+CH4 hydrate, but not 1-propanol+CH4 hydrate, was observed below about 110K. It is shown that the deformation of the host water cages of 2-propanol+CH4 hydrate can be explained by the restriction of the motion of 2-propanol within the 51264 host water cages. This result provides a low-temperature structure due to a temperature-induced symmetry-lowering transition of clathrate hydrate. This is the first example of a cubic structure of the common clathrate hydrate families at a fixed composition.

Original languageEnglish
JournalAngewandte Chemie - International Edition
Publication statusAccepted/In press - 2016



  • Clathrates
  • Gas hydrates
  • Inclusion compounds
  • Phase transitions
  • Powder X-ray diffraction

ASJC Scopus subject areas

  • Chemistry(all)
  • Catalysis

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