In 2018 we launched the ISIS Impact Awards for facility users, celebrating the scientific, social and economic impact generated by the user community. The winners of the three awards were announced at the UK Neutron and Muon Science and User Meeting (NMSUM) 2018.
The winner of the Science Award was given to Dr. Thomas Douglas Bennett, Hybrid Materials Group Leader at the University of Cambridge, for his work on modelling the structure of metal-organic framework glasses. Here we present the second of three case studies from the winning Science Award entry.
Metal-organic frameworks (MOFs) are a highly topical class of nanoporous materials containing inorganic nodes linked by organic ligands. Over 60,000 crystalline structures exist to date, finding commercial uses in a diverse array of applications such as fruit packaging, harmful gas storage and in vehicular H2 storage.
The major benefit of this beamtime was the elucidation of a structure of a melt-quenched metal-organic framework glass - the first example of the new hybrid glass family. Room temperature neutron data were collected and combined with that from I15-1 (XPDF), to aid in producing an atomic configuration for the glass via reverse Monte Carlo modelling. This model was then used with high temperature synchrotron data to produce an atomic configuration for MOF in the liquid state.
The work featured on the front cover of Nature Materials, and was highlighted in both in the same journal and also in Nature Reviews Materials. It was number 1 in the ISIS Neutron and Muon Source's top 10 most-discussed journal articles of 2017, and also featured in C&EN and Chemistry World.
A follow up work, using the same data collected, aimed at comparing RMC models of amorphous MOFs with the same chemical composition, though formed via different methodologies. This work has just been accepted into PCCP and is titled "Structural Investigations of Amorphous Metal-Organic Frameworks Formed Via Different Routes". D. A. Keen and T. D. Bennett, Phys Chem Chem Phys, 2018, 20, 7857-7861
A second paper, building on the work, and specifically focusing on the creation and characterisation of a blend of liquid MOFs, has recently been published in Nature Communications . PDF data was again collected, on a liquid mixture of a cobalt MOF and a zinc MOF, finding domain interlocking after quenching from the liquid phase.
More broadly, the work on amorphous MOFs has led to over 40 publications from this group.
2001-2007: Profs David Keen, Mathew Tucker, Martin Dove and Andrew Goodwin worked on the reverse Monte-Carlo modelling of disordered crystalline compounds [3.1] ad published the RMCProfile software [3.2], which enabled modelling of amorphous compounds.
2008 – 2012: Bennett (PhD student) under the supervision of Prof. Anthony Cheetham FRS and collaborating with Prof. David Keen and Prof. Andrew Goodwin, characterised a solid amorphous MOF [3.3] Other methods to induce amorphisation, including ball-milling and pressurisation, were also uncovered [3.4, 3.5].
2012-2015: Bennett (Research Fellow, Trinity Hall, Cambridge) led work in observing the melting process of a crystalline MOF of composition Zn(C3H3N2)2 [3.6] though no structural characterisation could be done at that time. A review article on the non-crystalline MOF state was produced in efforts to draw more researchers to the under developed field [3.7]. Computational work led by Coudert [3.8, 3.9] confirmed the structural collapse upon solvent removal of some MOFs, and pointed towards generalised metastability amongst MOFs. Melting was also found in the related coordination polymer family by Prof. Satoshi Horike [3.10], and a sol-gel route to hybrid glasses published by Yaghi and Angell [3.11].
2016-2018: Bennett (Royal Society University Research Fellow) with Prof. David Keen expanded the melting behavior of the ZIF family, drawing structural correlations between the identity of the organic linker used in the crystalline framework, and both melting and glass transition temperatures [3.12]. Positron annihilation lifetime measurements performed with colleagues at CSIRO confirmed the presence of appreciable porosity within the MOF-glass formed from ZIF-4 [3.13]
References to the research
3.1 M. G. Tucker, M. T. Dove and D. A. Keen, Journal of Applied Crystallography, 2001, 34, 630-638.
3.2 M. G. Tucker, D. A. Keen, M. T. Dove, A. L. Goodwin and Q. Hui, J Phys-Condens Mat, 2007, 19, 33.
3.3 T. D. Bennett, A. L. Goodwin, M. T. Dove, D. A. Keen, M. G. Tucker, E. R. Barney, A. K. Soper, E. G. Bithell, J. C. Tan and A. K. Cheetham, Physical Review Letters, 2010, 104, 115503.
3.4 T. D. Bennett, S. Cao, J. C. Tan, D. A. Keen, E. G. Bithell, P. J. Beldon, T. Friscic and A. K. Cheetham, J Am Chem Soc, 2011, 133, 14546-14549.
3.5 T. D. Bennett, P. Simoncic, S. A. Moggach, F. Gozzo, P. Macchi, D. A. Keen, J. C. Tan and A. K. Cheetham, Chem Commun, 2011, 47, 7983-7985.
3.6 T. D. Bennett, J. C. Tan, Y. Z. Yue, E. Baxter, C. D. Ducati, N. Terril, H. Y. Yeung, Z. Zhou, W. Chen, S. Henke, A. K. Cheetham and G. N. Greaves, Nat Commun, 2015, 6, 8079.
3.7 T. D. Bennett and A. K. Cheetham, Accounts Chem Res, 2014, 47, 1555-1562.
3.8 A. U. Ortiz, A. Boutin, A. H. Fuchs and F. X. Coudert, Journal of Physical Chemistry Letters, 2013, 4, 1861-1865.
3.9 L. B. du Bourg, A. U. Ortiz, A. Boutin and F. X. Coudert, Apl Materials, 2014, 2.
3.10 D. Umeyama, S. Horike, M. Inukai, T. Itakura and S. Kitagawa, J Am Chem Soc, 2015, 137, 864-870.
3.11 Y. Zhao, S.-Y. Lee, N. Becknell, O. M. Yaghi and C. A. Angell, J Am Chem Soc, 2016, 138, 10818–10821.
3.12 T. D. Bennett, Y. Z. Yue, P. Li, A. Qiao, H. Tao, G. N. Greaves, T. Richards, G. I. Lampronti, S. A. T. Redfern, F. Blanc, O. K. Farha, J. T. Hupp, A. K. Cheetham and D. A. Keen, J Am Chem Soc, 2016, 138, 3484-3492.
3.13 A. W. Thornton, K. E. Jelfs, K. Konstas, C. Doherty, A. J. Hill, A. K. Cheetham and T. D. Bennett, Chem Commun, 2016, 52, 3750-3753.
Sources to corroborate the impact
5.1 Nature Materials 16, pages 1149–1154 (2017)
5.2 Nature Reviews Materials 2, Article number: 17074 (2017)
5.3 Nature Materials 16, 1054–1055 (2017)
Communications, DOI: 10.1038/s41467-018-04553-6