Understanding the crystal structure of metal-organic framework thin film and the structural correlation with the underlying substrates

Metal-organic frameworks (MOFs) are nanoporous materials that are composed of metal ions connected with organic ligands leading to an ordered pore topology. Recently, we have developed a novel technique utilizing epitaxial substrates which promote in-plane nucleation and growth of 2D zeolitic imidazolate framework (ZIF) and succeeded in solving the structure of our 2DZIF film, which is different from its known 3D analog. We have extended the crystallization strategy to other promising MOFs (UiO-66-NH2, ZIF-7, CALF-20, MIL-53, MIL-101). Owing to the fact that MOFs are not stable under electron beam, we could not get the comprehensive understanding of 2D MOF structure including the in-plane and out-plane information. In particular, we are very interested in solving their crystal structure to understand the similarities and differences of the structure of 2D films and their 3D analog, and the correlation between orientation of 2D films and their underlying substrates.