Abstract
In situ powder X-ray diffraction and thermogravimetry show that the iron(III) carboxylate material MIL-53(Fe) expands in two steps upon exposure to methanol vapour to give a 'half open' phase and then a fully expanded structure; these correspond to the uptake of one and two molar equivalents of methanol, respectively. This knowledge allows interpretation of inelastic neutron scattering (INS) spectra, measured using TOSCA at ISIS, of the solid loaded with various amounts of water, methanol or d3-methanol (CD3OH), aided also by DFT simulation of INS spectra of the analogous MIL-53(Al) structure. The key signature of the expansion and contraction of the structure is the shift of bands in the 400 cm-1 region: these are assigned as due to the librations of the terephthalate rings, involving motions that result in distortion of the aromatic ring and a rocking motion of the aromatic ring about the bonds to the carboxylate groups.
| Original language | English |
|---|---|
| Pages (from-to) | 30-37 |
| Number of pages | 8 |
| Journal | Chemical Physics |
| Volume | 427 |
| DOIs | |
| State | Published - Dec 12 2013 |
| Externally published | Yes |
Funding
We thank STFC ISIS for provision of beamtime on TOSCA at ISIS and access to SCARF. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 228862. Some of the equipment used in materials characterisation at the University of Warwick was obtained through the Science City Advanced Materials project “Creating and Characterising Next Generation Advanced Materials” with support from Advantage West Midlands (AWM) and part funded by the European Regional Development Fund (ERDF).
| Funders | Funder number |
|---|---|
| FP7/2007 | |
| Seventh Framework Programme | 228862 |
| Seventh Framework Programme | |
| European Regional Development Fund |
Keywords
- Adsorption
- Neutron scattering
- Porosity
- Vibrational spectroscopy