A dynamic and multi-responsive porous flexible metal–organic material

Abstract

Stimuli responsive materials (SRMs) respond to environmental changes through chemical and/or structural transformations that can be triggered by interactions at solid-gas or solid-liquid interfaces, light, pressure or temperature. SRMs span compositions as diverse as organic polymers and porous inorganic solids such as zeolites. Metal–organic materials (MOMs), sustained by metal nodes and organic linker ligands are of special interest as SRMs. SR-MOMs have thus far tended to exhibit only one type of transformation, e.g. breathing, in response to one stimulus, e.g. pressure change. We report [Zn2(4,4′-biphenyldicarboxylate)2(4,4′-bis(4-pyridyl)biphenyl)]n, an SR-MOM, which exhibits six distinct phases and four types of structural transformation in response to various stimuli. The observed structural transformations, breathing, structural isomerism, shape memory effect, and change in the level of interpenetration, are previously known individually but have not yet been reported to exist collectively in the same compound. The multi-dynamic nature of this SR-MOM is mainly characterised by using in-situ techniques.

Isostructural NiII Metal–Organic Frameworks (MOFs) for Efficient Electrocatalysis of Oxygen Evolution Reaction and for Gas Sorption Properties

“…Consequently,t here is an urgentn eed to develop low cost, highly durable and novel crystalline solid materials exhibiting efficient catalytic activity,f rom earth-abundant elements as an alternative to RuO 2 and IrO 2 at ambient conditions. [18][19][20] In the past two decades, MOFs have been shown to have variousa pplicationss uch as for gas storage, gas separation, sensors, proton conduction and optoelectronic devices. [6,7] The composites of transitional metal oxides( TMOs) and nanomaterials are also foundt ob eg ood electrocatalysts for both OER and oxygen reductionr eaction( ORR).…”

Characterization of the adsorption site energies and heterogeneous surfaces of porous materials

“…It is also worth mentioning here about the recently appearing flexible or soft porous crystals or flexible MOFs whose pore volume and surface chemistry are sensitive to pressure. 87,88 The physics involved in such materials is in an emerging state and is still not definitively understood. Also, flexible porous materials lack the actual adsorption zone and the pore-widths are changed upon guest molecular adsorption/desorption.…”

Thermal Reactivity in Metal Organic Materials (MOMs): From Single-Crystal-to-Single-Crystal Reactions and Beyond

“…Importantly the process was followed by single crystal X-ray in a SCSC manner. Recently in 2018 Zaworotko and coworkers reported an interesting structural transformation focusing on the change in the level of interpenetration of the networks [68]. The network X-pcu-1-Zn-3i-α (7) transforms first to a desolvated phase at 323 K via a SCSC phase transformation X-pcu-1-Zn-3i-β (7') with a volume reduction of 13% relative to that of the solvated structure.…”

“…Pictures taken with an optical microscope showing the macroscopic variations suffered by the single crystal upon heating. This figure is reproduced from[68] with permission.…”