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Rich polymorphism of a metal-organic framework in pressure-temperature space

DOI: 10.1021/jacs.9b03234 DOI Help

Authors: Remo N. Widmer (University of Cambridge) , Giulio I. Lampronti (University of Cambridge) , Siwar Chibani (PSL University, CNRS) , Craig Wilson (Atomic Weapons Establishment) , Simone Anzellini (Diamond Light Source; CEA) , Stefan Farsang (University of Cambridge) , Annette K. Kleppe (Diamond Light Source) , Nicola P. M. Casati (Paul Scherrer Institute) , Simon Macleod (Atomic Weapons Establishment; The University of Edinburgh) , Simon A. T. Redfern (University of Cambridge) , François-Xavier Coudert (PSL University, CNRS) , Thomas D. Bennett (University of Cambridge)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Journal Of The American Chemical Society

State: Published (Approved)
Published: May 2019
Diamond Proposal Number(s): 19046

Open Access Open Access

Abstract: We present an in-situ powder X-ray diffraction study on the phase stability and polymorphism of the metal-organic framework ZIF-4, Zn(Imidazolate)2, at simultaneous high-pressure and high-temperature, up to 8 GPa and 600 °C. The resulting pressure-temperature phase diagram reveals four, previously unknown, high-pressure-temperature ZIF phases. The crystal structures of two new phases – ZIF-4-cp-II and ZIF-hPT-II – were solved by powder diffraction methods. The total energy of ZIF-4-cp-II was evaluated using density functional theory calculations and was found to lie in between that of ZIF-4 and the most thermodynamically stable polymorph, ZIF-zni. ZIF-hPT-II was found to possess a doubly-interpenetrated diamondoid-topology and is isostructural with previously reported Cd(Imidazolate)2 and Hg(Imidazolate)2 phases. This phase exhibited extreme resistance to both temperature and pressure. The other two new phases could be assigned with a unit cell and space group, though their structures remain unknown. The pressure-temperature phase diagram of ZIF-4 is strikingly complicated when compared with that of the previously investigated, closely related ZIF-62, and demonstrates the ability to traverse complex energy landscapes of metal-organic systems using the combined application of pressure and temperature.

Journal Keywords: Chemical structure; Physical and chemical processes; Mathematical methods; Phase transitions; Stability

Subject Areas: Chemistry, Materials

Instruments: I15-Extreme Conditions

Other Facilities: MS at Swiss Light Source

Added On: 29/05/2019 14:17


Discipline Tags:

Chemistry Materials Science Metal-Organic Frameworks Metallurgy Organometallic Chemistry

Technical Tags:

Diffraction X-ray Powder Diffraction