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ZIF‐8 was synthesized in supercritical carbon dioxide (scCO2). In situ powder X‐ray diffraction, ex situ microscopy, and simulations provide an encompassing view of the formation of ZIF‐8 and intermediary ZnO@ZIF‐8 composites in this nontraditional solvent. Time‐resolved imaging exposed divergent physicochemical reaction pathways from previous studies of the growth of anisotropic ZIF‐8 core@shell structures in traditional solvents. Synthetically relevant physiochemical properties of scCO2 were integrated into classical nucleation theory, relating interfacial forces, calculated through DFTB+ based molecular dynamics (MD), with 3D nucleation outcomes. The kinetics of crystallization were examined and displayed a characteristic signature of time‐ and temperature‐dependent mechanisms over the extent of the reaction. Lastly, it is shown that subtle factors, such as the extent of reaction and the size/shape of sacrificial templates can tailor ZIF‐8 composition and size, eliciting control over hierarchical porosity in a nonconventional green solvent. [ABSTRACT FROM AUTHOR]

Capture of CO2 from flue gas is considered to be a feasible approach to mitigate the effects of anthropogenic emission of CO2. Herein we report that an isostructural family of metal organic materials (MOMs) of general formula [M(linker)2(pillar)], linker = pyrazine, pillar = hexaflourosilicate and M = Zn, Cu, Ni and Co exhibits highly selective removal of CO2 from dry and wet simulated flue gas. Two members of the family, M = Ni and Co, SIFSIX-3-Ni and SIFSIX-3-Co, respectively, are reported for the first time and compared with the previously reported Zn and Cu analogs. [ABSTRACT FROM AUTHOR]

The chiral 3D MOFs resulted from the packing of chiral 1D SBBs were studied. It was demonstrated that the final packing pattern is sensitively dependent on the dimension of SBBs. In addition, we were able to identify a new plywood-like network from ligand 2H2exhibiting an unprecedented six-way chiral helical packing motif, which extends the list of invariant rod packings. [ABSTRACT FROM AUTHOR]

A metal–organic framework obtained from a flexible organic linker shows a breathing phenomenon upon adsorption of saturated hydrocarbons. [ABSTRACT FROM AUTHOR]

Two novel cadmium–organic frameworks containing achiral helical nanotubular channels, [Cd(HImDC)(S)]n(S = Im(1) and Py(2)), have been synthesized and characterized using single crystal X-ray diffraction, in which 1converts to 2upon refluxing 1 in pyridine solution with noticeable porosity and hydrogen uptake at medium pressure. [ABSTRACT FROM AUTHOR]

"Breathing" metal-organic frameworks (MOFs) are an emerging class of soft porous crystals (SPCs) with potential for high working capacity for gas storage applications. However, most breathing MOFs have low stability and/or low surface area. Here we report a water-stable, high surface area, breathing MOF of ftw topology, NU-1105. While Zr6-oxo clusters as nodes introduce water stability in NU-1105, its high surface area and breathing character stem from its pyrene-based tetracarboxylate (Py-FP) linkers, in which the fluorene units (F) in the FP "arms" play a key role in promoting breathing behavior. During gas sorption studies, the "closed pore" (cp) ↔ "open pore" (op) transition of NU-1105 occurs at a propane pressure of ~3 bar. At 1 bar, NU-1105 is in its cp form and adsorbs less propane than it would in its op form, highlighting improved working capacity. In situ powder X-ray diffraction during propane sorption was used to track the cp ↔ op transition, and molecular modeling was used to elucidate the structure of the op and cp forms of NU-1105. According to TD-DFT calculations, the proposed conformations of the Py-FP linkers in the op and cp forms are consistent with the measured excitation and emission spectra of the op and cp forms of NU-1105. Similar structural transitions are also observed in the porphyrinic MOF NU-1104 depending on the identity of the porphyrin core; we observed breathing behavior if the constituent Por-PTP linker is nonmetalated. [ABSTRACT FROM AUTHOR]