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Template‐Mediated Control over Polymorphism in the Vapor‐Assisted Formation of Zeolitic Imidazolate Framework Powders and Films
Author(s) -
Tu Min,
Kravchenko Dmitry E.,
Xia Benzheng,
RubioGiménez Víctor,
Wauteraerts Nathalie,
Verbeke Rhea,
Vankelecom Ivo F. J.,
Stassin Timothée,
Egger Werner,
Dickmann Marcel,
Amenitsch Heinz,
Ameloot Rob
Publication year - 2021
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202014791
Subject(s) - zeolitic imidazolate framework , physisorption , metal organic framework , microporous material , materials science , amorphous solid , chemical engineering , porosity , imidazolate , nanoporous , metastability , crystallography , chemistry , nanotechnology , inorganic chemistry , organic chemistry , adsorption , engineering , composite material
The landscape of possible polymorphs for some metal–organic frameworks (MOFs) can pose a challenge for controlling the outcome of their syntheses. Demonstrated here is the use of a template to control in the vapor‐assisted formation of zeolitic imidazolate framework (ZIF) powders and thin films. Introducing a small amount of either ethanol or dimethylformamide vapor during the reaction between ZnO and 4,5‐dichloroimidazole vapor results in the formation of the porous ZIF‐71 phase, whereas other conditions lead to the formation of the dense ZIF‐72 phase or amorphous materials. Time‐resolved in situ small‐angle X‐ray scattering reveals that the porous phase is metastable and can be transformed into its dense polymorph. This transformation is avoided through the introduction of template vapor. The porosity of the resulting ZIF powders and films was studied by N 2 and Kr physisorption, as well as positron annihilation lifetime spectroscopy. The templating principle was demonstrated for other members of the ZIF family as well, including the ZIF‐7 series, ZIF‐8_Cl, and ZIF‐8_Br.