(263g) Highly Stable Tunable Rare Earth Fcu-MOF Platform: Access to Adsorption Kinetics Driven Gas/Vapor Separations Via Pore Size Contraction

The Molecular Building Block (MBB) approach is a very powerful strategy that permits the fabrication of designed materials for specific applications.1 Indeed, our group has recently discovered and set up experimental conditions using a specific modulator, namely 2-Fluorobenzoic acid, that allows the formation of pre-targeted multi-nuclear rare earth (RE) Molecular Building Block (MBB) precursors to create and develop materials with targeted structural characteristics.2,3 The objective of this work is to demonstrate how the perfect structural control at the molecular level of a particular platform leads to the discovery of new materials with interesting potential for many gas/vapor separation applications. Accordingly, we applied this strategy to our well-known materials, namely RE-fcu-MOF, with the objective to obtain cavities with a specific size. In this work we examine the adsorption and the kinetic properties of different RE-fcu-MOFs assembled with different linkers. The ditopic linkers was successfully used to isolate rigid fcu MOF structures with custom designed cages that are accessible via narrow triangular cage windows with diameter of about 6, 5 and 3.8 Å. These newly unveiled fcu-MOFs analogues permitted the selective separation of different gases/vapors. The separation ability was evaluated by a combination of single and mixed gas/vapor adsorption and calorimetric studies.

References:

1. M. Eddaoudi, D. B. Moler, H. Li, B. Chen, T. M. Reineke, M. O'Keeffe, O. M. Yaghi, Accounts of Chemical Research 2001, 34, 319-330.

2. D.-X. Xue, A. J. Cairns, Y. Belmabkhout, L. Wojtas, Y. Liu, M. H. Alkordi, M. Eddaoudi, Journal of the American Chemical Society 2013, 135, 7660-7667.

3. D.-X. Xue, Y. Belmabkhout, O. Shekhah, H. Jiang, K. Adil, A. J. Cairns, M. Eddaoudi, Journal of the American Chemical Society 2015. DOI: 10.1021/ja5131403 .