Continuous Breathing Rare-Earth MOFs Based on Hexanuclear Clusters with Gas Trapping Properties

• DOI: 10.1021/jacs.1c03762
• Publication Date: 2021-06-29T19:32:26Z
• Authors: Giasemi K. Angeli; Edward Loukopoulos; Konstantinos Kouv...; Artemis Bosveli; Constantinos Tsan...; Emmanuel Tylianakis; George Froudakis; Pantelis N. Trika...
• Keywords: Crystal Engineering; Rational design

Guest responsive porous materials represent an important and fascinating class of multifunctional solids that have attracted considerable attention in recent years. An understanding how these structures form is essential toward their rational design, which a prerequisite for the development tailor-made advanced applications. We herein report novel series stable rare-earth (RE) MOFs show rare continuous breathing behavior unprecedented gas-trapping property. used asymmetric 4-c tetratopic carboxylate-based organic ligand capable affording highly crystalline upon controlled reaction with RE cations. These MOFs, denoted as RE-thc-MOF-1 (RE: Y3+, Sm3+, Eu3+, Tb3+, Dy3+, Ho3+, Er3+), feature hexanuclear RE6 clusters display unusual connectivity serve unique 8-c hemi-cuboctahedral secondary building block, resulting new (3,3,8)-c thc topology. Extensive single-crystal to structural analyses coupled detailed gas (N2, Ar, Kr, CO2, CH4, Xe) vapor (EtOH, CH3CN, C6H6, C6H14) sorption studies, supported by accurate theoretical calculations, shed light onto swelling behavior. The results reveal synergistic action involving steric effects, associated coordinated solvent molecules 2-fluorobenzoate (2-FBA) nonbridging ligands, well cation–framework electrostatic interactions. were able probe individual role 2-FBA ligands found both cooperatively control gas-breathing -trapping properties, while controls adsorption selectivity. findings provide opportunities design tunable RE-based flexible properties.