Identifying the Role of Terahertz Vibrations in Metal-Organic Frameworks: From Gate-Opening Phenomenon to Shear-Driven Structural Destabilization
Articolo
Data di Pubblicazione:
2014
Abstract:
We present an unambiguous identification of low-frequency terahertz vibrations in the archetypal
imidazole-based metal-organic framework (MOF) materials: ZIF-4, ZIF-7, and ZIF-8, all of which adopt a
zeolite-like nanoporous structure. Using inelastic neutron scattering and synchrotron radiation far-infrared
absorption spectroscopy, in conjunction with density functional theory (DFT), we have pinpointed all
major sources of vibrational modes. Ab initio DFT calculations revealed the complex nature of the
collective THz modes, which enable us to establish detailed correlations with experiments. We discover
that low-energy conformational dynamics offers multiple pathways to elucidate novel physical phenomena
observed in MOFs. New evidence demonstrates that THz modes are intrinsically linked, not only to
anomalous elasticity underpinning gate-opening and pore-breathing mechanisms, but also to shear-induced
phase transitions and the onset of structural instability.
Tipologia CRIS:
03A-Articolo su Rivista
Elenco autori:
Matthew R. Ryder;Bartolomeo Civalleri;Thomas D. Bennett;Sebastian Henke;Svemir Rudić;Gianfelice Cinque;Felix Fernandez-Alonso;Jin-Chong Tan
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