Particle size-dependent flexibility in DUT-8(Cu) pillared layer metal-organic framework

Research output: Contribution to journalResearch articleContributedpeer-review



The nature of metal in the isomorphous flexible metal-organic frameworks is often reported to influence flexibility and responsivity. A prominent example of such behaviour is the DUT-8(M) family ([M2(2,6-ndc)2(dabco)]n, 2,6-ndc = 2,6-naphthalene dicarboxylate, dabco = 1,4-diazabicyclo-[2.2.2]-octane), where the isostructural compounds with Ni, Zn, Co, and Cu in the paddle wheel cluster are known. The macro-sized crystals of Ni, Co, and Zn based compounds transform to the closed pore (cp) phase under desolvation and show typical gate opening behaviour upon adsorption. The choice of metal, in this case, allows the adjustment of switching kinetics, selectivity in adsorption, and gate-opening pressures. The submicron-sized crystals of of Ni, Co, and Zn based compounds remain in the open pore (op) phase after desolvation. In this contribution, we demonstrate that the presence of Cu in the paddle wheel leads to fundamentally different flexible behaviour. The DUT-8(Cu) desolvation does not lead to the formation of the cp phase, independent of the particle size regime. However, according to in situ powder diffraction analysis, the desolvated, macro-sized crystals of DUT-8(Cu)_op show breathing upon adsorption of CO2 at 195 K. The submicron-sized particles show rigid, nonresponsive behaviour.


Original languageEnglish
Pages (from-to)2816-2824
Number of pages9
JournalDalton transactions
Issue number9
Publication statusPublished - 31 Jan 2023

External IDs

PubMed 36752342
unpaywall 10.1039/d3dt00085k
WOS 000929095300001


ASJC Scopus subject areas


  • Crystal size, Adsorption, Separation, Copper, Mofs, Zn, Transitions, Efficient, Co, Cu