Vapor‐Phase Linker Exchange of the Metal–Organic Framework ZIF‐8: A Solvent‐Free Approach to Post‐synthetic Modification

Here we present a novel, solvent-free approach to post-synthetic linker exchange in ZIF-8 through exposure to linker vapor. As in the solvent-based approach, this vapor-phase linker exchange (VPLE) method retains the parent SOD topology and proceeds in a single-crystal to single-crystal manner. The scope of linkers that can be incorporated through VPLE was studied and criteria for the selection of further candidates were formulated. In large crystals, the incoming linker was found to form domains instead of distributing homogeneously, similar as for solution-based linker exchange. In contrast to the latter approach, VPLE yields a higher concentration of the incoming linker in the crystal core instead of the shell.

Download Full-text

Vapor-Phase Linker Exchange of the Metal-Organic Framework ZIF-8: A Solvent-Free Approach to Post-Synthetic Modification

10.26434/chemrxiv.8378894 ◽

2019 ◽

Author(s):

Joao Marreiros ◽

Lenz Van Dommelen ◽

Guillaume Fleury ◽

Rodrigo de Oliveira-Silva ◽

Timothée Stassin ◽

...

Keyword(s):

Single Crystal ◽

Vapor Phase ◽

Metal Organic Framework ◽

Solvent Free ◽

Metal Organic ◽

Crystal Core ◽

Linker Exchange ◽

Selection Of ◽

Organic Framework

Here we present a novel, solvent-free approach to post-synthetic linker exchange in ZIF-8 through exposure to linker vapor. As in the solvent-based approach, this vapor-phase linker exchange (VPLE) method retains the parent SOD topology and proceeds in a single-crystal to single-crystal manner. The scope of linkers that can be incorporated through VPLE was studied and criteria for the selection of further candidates were formulated. In large crystals, the incoming linker was found to form domains instead of distributing homogeneously, similar as for solution-based linker exchange. In contrast to the latter approach, VPLE yields a higher concentration of the incoming linker in the crystal core instead of the shell.

Download Full-text

Solvent-Free Powder Synthesis and MOF-CVD Thin Films of the Mesoporous Metal-Organic Framework MAF-6

10.26434/chemrxiv.9860891.v1 ◽

2019 ◽

Author(s):

Timothée Stassin ◽

Ivo Stassen ◽

Joao Marreiros ◽

Alexander John Cruz ◽

Rhea Verbeke ◽

...

Keyword(s):

Vapor Phase ◽

Metal Organic Framework ◽

Chemical Vapor ◽

Uptake Capacity ◽

Powder Synthesis ◽

Crystalline Films ◽

Metal Organic ◽

Mesoporous Metal ◽

First Time ◽

Organic Framework

A simple solvent- and catalyst-free method is presented for the synthesis of the mesoporous metal-organic framework (MOF) MAF-6 (RHO-Zn(eIm)2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤ 100 °C. By translating this method to a chemical vapor deposition (CVD) protocol, mesoporous crystalline films could be deposited for the first time entirely from the vapor phase. A combination of PALS and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diam. ~2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by XRD, TGA, SEM, FTIR, PDF and EXAFS. The exceptional uptake capacity of the mesoporous MAF-6 in comparison to the microporous ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows.

Download Full-text