High Pressure In Situ Single‐Crystal X‐Ray Diffraction Reveals Turnstile Linker Rotation Upon Room‐Temperature Stepped Uptake of Alkanes

Abstract

The rare availability of suitable single-crystal X-ray diffraction (SCXRD) structural data allows for the direct interpretation of the response of af ramework to gas sorption and mayl ead to the development of improved functional porous materials.W er eport an in situ SCXRD structural investigation of af lexible MOF subjected to methane,e thane, propane,a nd butane gas pressures.S upporting theoretical investigations indicate weak host-guest interactions for the crystallographically modelled gaseous guests and, in addition, reveal that at urnstile mechanism facilitates the transport of alkanes through the seemingly nonporous system. Inflections present in the adsorption isotherms are furthermore rationalized as due to gate-opening,but without the expected creation of new accessible space.

Metallocavitins as Promising Industrial Catalysts: Recent Advances

“…On the other hand, adaptability is a hallmark of enzymes. Flexible cavitins mimic these owing to structural changes that accompany adsorption and desorption steps (Heerden et al, 2021). Cavitins are able to create chiral molecular catalysts via preferential secondary interactions between the substrate and framework that induce enantioselectivities not achievable in homogenous systems.…”

MOF-Based Dual Sensor for the Electrochemical and Fluorescence Detection of Nicotine

“…Metal−organic frameworks (MOFs), inorganic−organic hybrid porous materials with tuneable properties, have been explored for various applications. 20,21 These can also be promising candidates as fluorescent and electrochemical sensors due to the feasibility of placing fluorescent linkers and metal/ligand redox centers inside the framework. MOFs have been explored for sensing of diverse analytes, 22−24 but there is only a handful of reports on nicotine detection using MOFs.…”

“…Recently, many researchers explored electrochemical sensing of nicotine using glassy carbon electrodes (GCE), carbon paste electrodes, and pencil graphite electrodes as unmodified electrodes. − Numerous composites have been prepared as electrochemical sensors using conducting materials such as graphene, multiwalled carbon nanotubes, metal oxides, nanoparticles, nanotubes, and polymers. − Such sensors, despite their better current sensitivities, involve tedious sample preparations. Metal–organic frameworks (MOFs), inorganic–organic hybrid porous materials with tuneable properties, have been explored for various applications. , These can also be promising candidates as fluorescent and electrochemical sensors due to the feasibility of placing fluorescent linkers and metal/ligand redox centers inside the framework. MOFs have been explored for sensing of diverse analytes, − but there is only a handful of reports on nicotine detection using MOFs. − Recently, our group has also investigated MOFs for fluorescence and electrochemical sensing applications. , Encouraged by our recent findings, we have designed the first MOF-based dual sensor for nicotine detection.…”

Significance of an Environmental Gas Cell to Obtain a Fully Dehydrated Form and CO2-Pressurized Structure of a Metal–Organic Framework Using In Situ Single-Crystal X-ray Diffraction at 298 K

“…In the case of porous materials, often we observed that, once the solvent molecules are removed from the lattice, it loses its crystal singularity, leading to a poor or no diffraction pattern in single-crystal X-ray diffraction (SCXRD) analysis . So, it has been always a challenge to obtain fully desolvated forms of porous compounds using SCXRD analysis . In addition even after full desolvation, some porous materials, when exposed to an open environment or air, tend to show affinity toward moisture adsorption from the atmosphere/air .…”

“…8 So, it has been always a challenge to obtain fully desolvated forms of porous compounds using SCXRD analysis. 9 In addition even after full desolvation, some porous materials, when exposed to an open environment or air, tend to show affinity toward moisture adsorption from the atmosphere/ air. 10 Such cases, especially where the sample preparation needs exposure to an open environment or air even for a very small period of time, often lead to the wrong interpretation of the data.…”