Noncovalent interaction guided selectivity of haloaromatic isomers in a flexible porous coordination polymer.

Porous, supramolecular structures exhibit preferential encapsulation of guest molecules, primarily by means of differences in the order of (noncovalent) interactions. The encapsulation preferences can be for geometry (dimension and shape) and the chemical nature of the guest. While geometry-based sorting is relatively straightforward using advanced porous materials, designing a "chemical nature" specific host is not.

Tailoring a robust Al-MOF for trapping CH and CH towards efficient CH purification from quaternary mixtures.

Light hydrocarbon separation is considered one of the most industrially challenging and desired chemical separation processes and is highly essential in polymer and chemical industries. Among them, separating ethylene (CH) from C2 hydrocarbon mixtures such as ethane (CH), acetylene (CH), and other natural gas elements (CO, CH) is of paramount importance and poses significant difficulty. We demonstrate such separations using an Al-MOF synthesised earlier as a non-porous material, but herein endowed with hierarchical porosity created under microwave conditions in an equimolar water/ethanol solution.

Gate Opening without Volume Change Triggers Cooperative Gas Interactions, Underpins an Isotherm Step in Metal-Organic Frameworks.

Three halogenated metal-organic frameworks (MOFs) reported recently exhibited a second step in their CO gas adsorption isotherms. The emergence of halogen-bonding interactions beyond a threshold gas pressure between the framework halogen and the CO guest was conjectured to be the underlying reason for the additional step in the isotherm. Our investigation employing periodic density functional theory calculations did not show significant interactions between the halogen and CO molecules.

A Dynamic Chemical Clip in Supramolecular Framework for Sorting Alkylaromatic Isomers using Thermodynamic and Kinetic Preferences.

Adsorptive chemical separation is at the forefront of future technologies, for use in chemical and petrochemical industries. In this process, a porous adsorbent selectively allows a single component from a mixture of three or more chemical components to be adsorbed or permeate. To separate the unsorted chemicals, a different adsorbent is needed.

Unraveling the Sorption Mechanism of CO in a Molecular Crystal without Intrinsic Porosity.

The facile uptake of CO gas in a nonporous molecular crystal constituted by long molecules with carbazole and ethynylphenyl moieties was reported in experiments recently. Herein, the mechanism of gas uptake by this crystal is elucidated using atomistic molecular simulations. The uptake of CO is shown to be facilitated by (i) the capacity of the crystal to expand in volume because of weak intermolecular interactions, (ii) the parallel orientation of the long molecules in the crystal, and (iii) the ability of the molecule to marginally bend, yet not lose crystallinity because of the anchoring of the terminal carbazole groups.