Spectroscopic observation of H2 migration in structure-I clathrate hydrate.

We demonstrate the spectroscopic observation of H₂ migration in the binary structure-I (sI) clathrate hydrate. The H₂ molecules captured into sI small cage (sI-S) at lower temperature migrate to sI large cage (sI-L) through shared pentagonal face of 5¹²6² cage. The hexagonal faces of 5¹²6² cage provide the windows essential for creating continuous diffusion paths for H₂ molecules. It is essential to realize that the vacant channels formed by the linkage of specific cages can play an important role in guest diffusion pathways and occupancy occurring in a complex clathrate hydrate matrix. [ABSTRACT FROM AUTHOR]