Anisotropic Thermal and Guest-Induced Responses of an Ultramicroporous Framework with Rigid Linkers

Josie E Auckett; Samuel G Duyker; Ekaterina I Izgorodina; Chris S Hawes; David R Turner; Stuart R Batten; Vanessa K Peterson

doi:10.1002/chem.201800261

Anisotropic Thermal and Guest-Induced Responses of an Ultramicroporous Framework with Rigid Linkers

Chemistry. 2018 Apr 3;24(19):4774-4779. doi: 10.1002/chem.201800261. Epub 2018 Mar 8.

Authors

Josie E Auckett¹, Samuel G Duyker², Ekaterina I Izgorodina³, Chris S Hawes^{3

4}, David R Turner³, Stuart R Batten³, Vanessa K Peterson¹

Affiliations

¹ Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, New South Wales, 2234, Australia.
² School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia.
³ School of Chemistry, Monash University, Melbourne, Victoria, 3800, Australia.
⁴ Present address: School of Chemical and Physical Sciences, Keele University, Staffordshire, ST5 5BG, UK.

PMID: 29450922
DOI: 10.1002/chem.201800261

Abstract

The interdependent effects of temperature and guest uptake on the structure of the ultramicroporous metal-organic framework [Cu₃ (cdm)₄ ] (cdm=C(CN)₂ (CONH₂ )^- ) were explored in detail by using in situ neutron scattering and density functional theory calculations. The tetragonal lattice displays an anisotropic thermal response related to a hinged "lattice-fence" mechanism, unusual for this topology, which is facilitated by pivoting of the rigid cdm anion about the Cu nodes. Calculated pore-size metrics clearly illustrate the potential for temperature-mediated adsorption in ultramicroporous frameworks due to thermal fluctuations of the pore diameter near the value of the target guest kinetic diameter, though in [Cu₃ (cdm)₄ ] this is counteracted by a competing contraction of the pore with increasing temperature as a result of the anisotropic lattice response.

Keywords: density functional calculations; gas sorption; metal-organic frameworks; negative thermal expansion; neutron diffraction.