Responses of Defect-Rich Zr-Based Metal–Organic Frameworks toward NH₃ Adsorption

Understanding structural responses of metal-organic frameworks (MOFs) to external stimuli such as the inclusion guest molecules and temperature/pressure has gained increasing attention in many applications, for example, manipulation manifesto smart materials gas storage, energy controlled drug delivery, tunable mechanical properties, molecular sensing, name but a few. Herein, neutron synchrotron diffractions along with Rietveld refinement density functional theory calculations have been used elucidate responsive adsorption behaviors defect-rich Zr-based MOFs upon progressive incorporation ammonia (NH3) variable temperature. UiO-67 UiO-bpydc containing biphenyl dicarboxylate bipyridine linkers, respectively, were selected, results establish paramount influence linkers on their NH3 affinity, which leads stimulus-tailoring properties gate-controlled porosity by dynamic linker flipping, disorder, rigidity. Despite similarities, we show first time dramatic alteration profiles when phenyl groups are replaced organic linker. These controls stem from controlling degree H-bonding networks/distortions between scaffold adsorbed without significant change pore volume unit cell parameters. Temperature-dependent diffraction also reveals NH3-induced rotational motions linkers. We demonstrate that flexibility can critically be affected type quantity small molecules. This strikes delicate control material at level.