Post‐Synthetic Modification Unlocks a 2D‐to‐3D Switch in MOF Breathing Response: A Single‐Crystal‐Diffraction Mapping Study

Post-synthetic modification (PSM) of the interpenetrated diamondoid metal–organic framework (Me2NH2)[In(BDC-NH2)2] (BDC-NH2=aminobenzenedicarboxylate) SHF-61 proceeds quantitatively in a single-crystal-to-single-crystal manner to yield acetamide derivative (Me2NH2)[In(BDC-NHC(O)Me)2] SHF-62. Continuous breathing behaviour during activation/desolvation is retained upon PSM, but pore closing now leads ring-flipping avert steric clash amide methyl groups modified ligands. This triggers reduction amplitude deformation two dimensions associated with diameter, large increase third dimension length. The MOF thereby converted from predominantly 2D (in SHF-61) distinctly 3D motion SHF-62) indicating decoupling pore-width and pore-length motions. These motions have been mapped by series single-crystal diffraction studies.