IsoreticularExpansion in Porous Aluminum(III) andGallium(III) Phosphonates: Synthesis, Structure, and Properties
Abstract We report the synthesis, structural elucidation, and establishment of structure−property relationships for two metal−organic frameworks (MOFs), [M(OH)(H2BPD)]·xH2O (M = Al3+, Ga3+, x = 11–13), denoted as M-CAU-67, employing the ditopic linker molecule N,N′-4,4′ bipiperidine bis(methylenephosphonic acid) (H4BPD). The title compounds can be synthesized on a milligram scale under hydrothermal conditions, while gram-scale synthesis was realized under reflux conditions. Single-crystal X-ray diffraction (SCXRD) revealed an isoreticular, expanded MIL-91 type structure, representing a rare case of isoreticular expansion in porous metal phosphonates. The framework structure was confirmed by Rietveld refinement against powder X-ray diffraction (PXRD) data and further validated by solid-state NMR spectroscopy (31P MAS, 27Al 3Q MAS). Solvent-exchange experiments and variable-humidity/temperature PXRD data revealed high framework flexibility. The compounds show permanent microporosity and a complex, polarity- and size-dependent sorption behavior toward gases and vapors.
Authors
- Michael Tiemann (ORCID: https://orcid.org/0000-0003-1711-2722)
- Nick Gys (ORCID: https://orcid.org/0000-0003-1464-6331)
- Felix Steinke
- Rob Ameloot (ORCID: https://orcid.org/0000-0003-3178-5480)
- Wouter Marchal (ORCID: https://orcid.org/0000-0001-5105-8112)
- Elien Derveaux (ORCID: https://orcid.org/0000-0002-3243-7309)
- Christian Näther (ORCID: https://orcid.org/0000-0001-8741-6508)
- Sebastian Henke (ORCID: https://orcid.org/0000-0003-1502-6038)
- Jesús Gándara-Loe (ORCID: https://orcid.org/0000-0003-1334-4788)
- Norbert Stock (ORCID: https://orcid.org/0000-0002-0339-7352)
- Sebastian Mangelsen (ORCID: https://orcid.org/0000-0003-2121-9514)
- Peter Adriaensens (ORCID: https://orcid.org/0000-0003-4183-0150)
- Roderick Adams (ORCID: https://orcid.org/0000-0002-3376-3632)
- Tom Hauffman (ORCID: https://orcid.org/0000-0002-3456-0271)
- Frederik Tielens (ORCID: https://orcid.org/0000-0002-6760-6176)
- Jennifer Theissen (ORCID: https://orcid.org/0000-0001-7374-8819)
- Tobias Wagner (ORCID: https://orcid.org/0009-0006-6764-0979)
- Marvin Radke
- Christian Nelle (ORCID: https://orcid.org/0009-0005-8704-435X)
- Jasper Lopau
- Jörn Struve
Institutions
- Vrije Universiteit Brussel (BE)
- TU Dortmund University (DE)
- Paderborn University (DE)
- Christian-Albrechts-Universität zu Kiel (DE)
- Hasselt University (BE)
- KU Leuven (BE)
Publication Details
- Journal
- Chemistry of Materials
- Published
- 2026-08-03
- DOI
- https://doi.org/10.1021/acs.chemmater.6c01336
- Primary Topic
- Metal-Organic Frameworks: Synthesis and Applications
- Type
- article
- Field-Weighted Citation Impact
- 0.00