Discrimination of xylene isomers in a stacked coordination polymer.

The separation and purification of xylene isomers is an industrially important but challenging process. Developing highly efficient adsorbents is crucial for the implementation of simulated moving bed technology for industrial separation of these isomers. Herein, we report a stacked one-dimensional coordination polymer {[Mn(dhbq)(HO)], Hdhbq = 2,5-dihydroxy-1,4-benzoquinone} that exhibits an ideal molecular recognition and sieving of xylene isomers.

High-Performance Selective CO Capture on a Stable and Flexible Metal-Organic Framework via Discriminatory Gate-Opening Effect.

Selective CO capture is of great significance for environmental protection and industrial demand. Here, we report a stable and flexible metal-organic framework (MOF) with excellent water/moisture stability, namely, ZnDatzBdc, that enables high-performance selective CO capture from N and CH via a discriminatory gate-opening effect. ZnDatzBdc shows reversible structural transformation between the open-phase (OP) state and the close-phase (CP) state, owing to the synergistic effect of breakage/re-formation of intraframework hydrogen bonds and the rotation of the phenyl rings.

Metal-Organic Framework Based Hydrogen-Bonding Nanotrap for Efficient Acetylene Storage and Separation.

The removal of carbon dioxide (CO) from acetylene (CH) is a critical industrial process for manufacturing high-purity CH. However, it remains challenging to address the tradeoff between adsorption capacity and selectivity, on account of their similar physical properties and molecular sizes. To overcome this difficulty, here we report a novel strategy involving the regulation of a hydrogen-bonding nanotrap on the pore surface to promote the separation of CH/CO mixtures in three isostructural metal-organic frameworks (MOFs, named MIL-160, CAU-10H, and CAU-23, respectively).

Flexible Zn-MOF with Rare Underlying Topology for Effective Separation of C6 Alkane Isomers.

Adsorptive separation by porous solids provides an energy-efficient alternative for the purification of important chemical species compared to energy-intensive distillations. Particularly, the separation of linear hexane isomers from its branched counterparts is crucial to produce premium grade gasoline with high research octane number (RON). Herein, we report the synthesis of a new, flexible zinc-based metal-organic framework, [Zn(μ-OH)(adtb)(HO)·5 DMA] (Zn-adtb), constructed from a butterfly shaped carboxylate linker with underlying (4,8)-connected topology capable of separating the C6 isomers HEX, 3MP, and 23DMB.

Ultrastable Zirconium-Based Cationic Metal-Organic Frameworks for Perrhenate Removal from Wastewater.

The effective removal of radioactive TcO anion from nuclear wastewater remains a very difficult unsolved problem. Functional adsorbent materials with high stability, anion-exchange capacity, excellent selectivity, and recyclability are much needed to solve this problem. In this work, we designed two stable cationic metal-organic frameworks (MOFs)-Zr-tcbp-Me and Zr-tcpp-Me-for possible use as adsorbent materials to remove TcO.

Calcium-Based Metal-Organic Frameworks and Their Potential Applications.

Metal-organic frameworks (MOFs) built on calcium metal (Ca-MOFs) represent a unique subclass of MOFs featuring high stability, low toxicity, and relatively low density. Ca-MOFs show considerable potential for molecular separations, electronic, magnetic, and biomedical applications, although they are not investigated as extensively as transition metal-based MOFs. Compared to MOFs made of other groups of metals, Ca-MOFs may be particularly advantageous for certain applications such as adsorption and storage of light molecules because of their gravimetric benefit, and drug delivery due to their high biocompatibility.

A combined experimental/computational study on the adsorption of organosulfur compounds over metal-organic frameworks from fuels.

This work investigates the adsorption of organosulfur compounds in model fuels over metal-organic frameworks (MOFs) using a combined experimental/computational approach. Adsorption isotherms of three MOFs, MIL-101(Cr), MIL-100(Fe), and Cu-BTC, follow the Langmuir isotherm models, and Cu-BTC shows the highest adsorption capacity for both dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT), ascribing to the highest density of adsorption sites and fairly strong adsorption sites on Cu-BTC. Experimental results show adsorption selectivity of various compounds in model fuels follows the order of quinoline (Qu) > indole (In) > DBT > 4,6-DMDBT > naphthalene (Nap), which is consistent with the order of calculated binding energies.