TY  - JOUR
A1  - Mondal, Suvendu Sekhar
A1  - Dey, Subarna
A1  - Attallah, Ahmed G.
A1  - Krause-Rehberg, Reinhard
A1  - Janiak, Christoph
A1  - Holdt, Hans-Jürgen
T1  - Insights into the pores of microwave-assisted metal-imidazolate frameworks showing enhanced gas sorption
T2  - Dalton transactions : a journal of inorganic chemistry, including bioinorganic, organometallic, and solid-state chemistry
N2  - Microwave heating (MW)-assisted synthesis has been widely applied as an alternative method for the chemical synthesis of organic and inorganic materials. In this work, we report MW-assisted synthesis of three isostructural 3D frameworks with a flexible linker arm of the chelating linker 2-substituted imidazolate- 4-amide-5-imidate, named IFP-7-MW (M = Zn, R = OMe), IFP-8-MW (M = Co; R = OMe) and IFP-10-MW (M = Co; R = OEt) (IFP = Imidazolate Framework Potsdam). These chelating ligands were generated in situ by partial hydrolysis of 2-substituted 4,5-dicyanoimidazoles under MW-and also conventional electrical heating (CE)-assisted conditions in DMF. The structure of these materials was determined by IR spectroscopy and powder X-ray diffraction (PXRD) and the identity of the materials synthesized under CE-conditions was established. Materials obtained from MW-heating show many fold enhancement of CO2 and H-2 uptake capacities, compared to the analogous CE-heating method based materials. To understand the inner pore-sizes of IFP structures and variations of gas sorptions, we performed positron annihilation lifetime spectroscopy (PALS), which shows that MW-assisted materials have smaller pore sizes than materials synthesized under CE-conditions. The "kinetically controlled" MW-synthesized material has an inherent ability to trap extra linkers, thereby reducing the pore sizes of CE-materials to ultra/micropores. These ultramicropores are responsible for high gas sorption.
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/46723
SN  - 1477-9226
SN  - 1477-9234
VL  - 46
SP  - 4824
EP  - 4833
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -