Linker Exchange via Migration along the Backbone in Metal-Organic Frameworks.
J Am Chem Soc
; 143(28): 10541-10546, 2021 07 21.
Article
in En
| MEDLINE
| ID: mdl-34228932
ABSTRACT
In metal-organic frameworks (MOFs), organic linkers are subject to postsynthetic exchange (PSE) when new linkers reach sites of PSE by diffusion. Here, we show that during PSE, a bulky organic linker is able to penetrate narrow-window MOF crystals. The bulky linker migrates by continuously replacing the linkers gating the otherwise impassable windows and serially occupying an array of backbone sites, a mechanism we term through-backbone diffusion. A necessary consequence of this process is the accumulation of missing-linker defects along the diffusion trajectories. Using fluorescence intensity and lifetime imaging microscopy, we found a gradient of missing-linker defects from the crystal surface to the interior, consistent with the spatial progression of PSE. Our success in incorporating bulky functional groups via PSE extends the scope of MOFs that can be used to host sizable, sophisticated guest species, including large catalysts or biomolecules, which were previously deemed only incorporable into MOFs of very large windows.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Am Chem Soc
Year:
2021
Type:
Article
Affiliation country:
Germany