Structure Regulation of MOF Nanosheet Membrane for Accurate H2 /CO2 Separation

High-purity H₂ production accompanied with a precise decarbonization opens an avenue to approach a carbon-neutral society. Metal-organic framework nanosheet membranes provide great opportunities for an accurate and fast H₂ /CO₂ separation, CO₂ leakage through the membrane interlayer galleries decided the ultimate separation accuracy. Here we introduce low dose amino side groups into the Zn₂ (benzimidazolate)₄ conformation. Physisorbed CO₂ served as interlayer linkers, gently regulated and stabilized the interlayer spacing. These evoked a synergistic effect of CO₂ adsorption-assisted molecular sieving and steric hinderance, whilst exquisitely preserving apertures for high-speed H₂ transport. The optimized amino membranes set a new record for ultrathin nanosheet membranes in H₂ /CO₂ separation (mixture separation factor: 1158, H₂ permeance: 1417 gas permeation unit). This strategy provides an effective way to customize ultrathin nanosheet membranes with desirable molecular sieving ability.

A bio-relevant supramolecular Co(ii)-complex for selective fluorescence sensing of μM range inorganic As(iii) in aqueous medium and its intracellular tracking in bacterial systems

A bio-relevant fluorescent supramolecular Co(ii)-complex selectively detects μM range toxic inorganic As(iii) in water and in bacterial systems.

Is [N+−H···O] Hydrogen Bonding the Most Important Noncovalent Interaction in Macrocycle−Dibenzylammonium Ion Complexes?

We report a new host molecule in which one diethylene glycol chain (i.e., a loop possessing only three oxygen atoms) incorporated along with two phenolic aromatic rings is linked by a xylene spacer into a macroring. The design of the molecular structure of this macrocycle "amplifies" any potential [cation...pi], [N+-H...pi], and [N+C-H...pi] interactions between the dibenzylammonium (DBA+) ion and the phenolic rings of the macrocycle; as such, these species display a very strong binding affinity in CD3NO2 (Ka = 15,000 M(-1)). The macroring also coordinates to bipyridinium ions in a [2]pseudorotaxane fashion, which makes it the smallest macrocycle (i.e., a 25-membered ring) known to complex both DBA+ and bipyridinium ions in solution. To confirm unambiguously that these pseudorotaxanes exist in solution, we synthesized their corresponding interlocked molecules, namely rotaxanes and catenanes.