Flexibility in Metal–Organic Frameworks: A Basic Understanding

Abstract

Much has been written about the fundamental aspects of the metal–organic frameworks (MOFs). Still, details concerning the MOFs with structural flexibility are not comprehensively understood. However, a dramatic increase in research activities concerning rigid MOFs over the years has brought deeper levels of understanding for their properties and applications. Nonetheless, robustness and flexibility of such smart frameworks are intriguing for different research areas such as catalysis, adsorption, etc. This manuscript overviews the different aspects of framework flexibility. The review has touched lightly on several ideas and proposals, which have been demonstrated within the selected examples to provide a logical basis to obtain a fundamental understanding of their synthesis and behavior to external stimuli.

Facile synthesis of PEDOT-rGO/HKUST-1 for high performance symmetrical supercapacitor device

“…A slight increment in capacitance retention (first 300 cycles) can be noticed in both HKUST-1 (121.3%) and PrGO/HKUST-1 (103.2%), indicating a self-activation process where electrolyte ions continuously penetrate all the active sites of the composite 62 . During the long-term cycling stability, HKUST-1 depicts an obvious decrease in specific capacitance compared to PrGO/HKUST-1 due to the swelling and shrinking properties of HKUST-1 during the redox reaction 63 . The inset of Fig.…”

Characterization of an Isostructural MOF Series of Imidazolate Frameworks Potsdam by Means of Sorption Experiments with Water Vapor

“…CO 2 not only has a smaller kinetic diameter (d K ) in principle (see Table 1), but is also kinetically more active at an experimental temperature of 273.15 K compared to N 2 at 77.4 K and therefore penetrates micropores more easily. Another reason for the better resolution of the micropore range is given due to a temperature-related flexibility of the adsorbents used, as it has often been reported for MOFs [47][48][49][50][51] as well as for IFP compounds [52,53]. However, isotherms derived from water vapor, which exhibits the smallest kinetic diameter of the selected adsorptives, allow a better insight in local phenomena.…”

Poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal-organic frameworks as a high-performance symmetrical supercapacitor device

“…A slight increment in capacitance retention (first 300 cycles) can be noticed in both HKUST-1 (121.3%) and PrGO/HKUST-1 (103.2%), indicating a self-activation process where electrolyte ions continuously penetrate all the active sites of the composite 47 . During the long-term cycling stability, HKUST-1 depicts an obvious decrease in specific capacitance compared to PrGO/HKUST-1 due to the swelling and shrinking properties of HKUST-1 during the redox reaction 48 . The high cycling stability of PrGO/HKUST-1 is due to the presence of rGO, where it is able to provide high mechanical strength to the composite…”