Stimuli-Responsive Framework Behaviour

The group are interested in studying the response of hybrid frameworks to external stresses such as shear, pressure and temperature. We use in-situ (e.g. variable temperature / variable pressure) experiments in both our laboratory and at national facilities, to analyze structural changes which occur on exposure to these stimuli.

The response to temperature is of particular interest, given our extensive work on the thermal stability of MOFs (1), and the formation of high temperature liquids from metal-organic coordination cages (MOCs), MOFs and hybrid perovskites. Liquids formed from MOCs have been shown to possess potential as CFC sorbents (2).

The group have, in collaboration with scientists from the Diamond Synchrotron here in the UK, produced the first high-pressure high-temperature phase diagrams of MOFs. The study of MOFs under ‘Extreme Conditions’ such as those found beneath the Earth’s crust, have in some cases revealed the existence of exotic polymorphs (3), and in others demonstrated unusual physical phenomena such as a negative melting curves (4).

Selected References

(1) The Thermal Stability of Metal-Organic Frameworks

C. Healy, K. M. Patil, B. H. Wilson,L. Hermanspahn, N. C. Harvey-Reid, B. I. Howard, C. Kleinjan, J. Kolien, F. Payet, S. G. Telfer, P. E. Kruger* and T, D. Bennett*, Coord. Chem. Rev., 2020, 419, 213388..

(2) Coordination cages as a scaffold for permanently porous liquids

L. Ma, A. B. Grommet, C. J. E. Haynes, A. Walczak, C. C. Parkins, L. Longley, A. Tron, T. D. Bennett* and J. R. Nitschke*. Nat. Chem., 2020, 12, 270-275.

(3) Rich Polymorphism of a metal-organic framework in pressure-temperature space

R. N. Widmer, G. I. Lampronti, S. Chibani, C. W. Wilson, S. Anzellini, S. Farsang, A. K. Kleppe, N. P. M. Casati, S. G. MacLeod, S. A. T. Redfern, F. X. Coudert and T. D. Bennett*, J. Am. Chem. Soc., 2019, 141, 9330-9337.

(4) Pressure promoted low-temperature melting of metal-organic frameworks

R. N. Widmer, G. I. Lampronti, S. Anzellini, R. Gaillac, S. Farsang, C. Zhou, A. M. Belenguer, H. Palmer, A. K. Kleppe, M. T. Wharmby, S. A. T. Redfern, F. X. Coudert, S. G. Macleod, T. D. Bennett,* Nat. Mater., 2019, 18, 370-376.