A three-dimensional water-stable cationic metal-organic framework (MOF) pillared by a neutral ligand and with Ni(II)  metal nodes has been synthesized employing a rational design approach. Owing to the ordered arrangement of the uncoordinated tetrahedral sulfate (SO4 (2-) ) ions in the channels, the compound has been employed for aqueous-phase ion-exchange applications. The compound exhibits rapid and colorimetric aqueous-phase capture of environmentally toxic oxoanions (with similar geometries) in a selective manner. This system is the first example of a MOF-based system which absorbs both dichromate (Cr2 O7 (2-) ) and permanganate (MnO4 (-) ) ions, with the latter acting as a model for the radioactive contaminant pertechnetate (TcO4 (-) ).

Chemical separation has great importance in industrial applications. Separation of xylene isomers still prevails to be one of the most important challenges in chemical industry, due to the large amount of commercial use of p-xylene in the production of beverage bottles, fibers and films. A novel Zn(II)-based dynamic coordination framework based on flexible ether-linkage, exhibiting selective adsorption of p-Xylene over its congener C8-alkyl aromatic isomers at ambient conditions is reported. Notably, no dynamic structure based MOF compound is known in the literature which shows clear preference of p-xylene over other isomers. This type of framework-breathing and guest-induced reversible solid-state structural transformations with unique adsorption selectivity can be exploited purposefully to develop smart functional host materials capable of industrially important chemical separations.

Guest and anion dependent: Structural dynamism and luminescence of a cationic porous framework (see picture) are investigated by different analytical techniques, such as single‐crystal‐to‐single‐crystal structural transformation. The compound shows size‐selective sorption of hydrophobic guest molecules, easy exchange of anions of the framework, and interesting anion‐responsive luminescence.

Highly selective and sensitive aqueous phase-detection of well-known nitro explosive environmental pollutant 2,4,6-Trinitrophenol (TNP) by a water-stable, porous luminescent metal-organic framework has been reported. The presence of guest accessible aliphatic amine functionality in the MOF channels has been strategically harnessed for serving the purpose of exclusive TNP-sensing in water even in concurrent presence of other nitro aromatic and nitro aliphatic analytes.

Derived from a strategically chosen hexafluorinated dicarboxylate linker aimed at the designed synthesis of a superhydrophobic metal-organic framework (MOF), the fluorine-rich nanospace of a water-stable MOF (UHMOF-100) exhibits excellent water-repellent features. It registered the highest water contact angle (≈176°) in the MOF domain, marking the first example of an ultrahydrophobic MOF. Various experimental and theoretical studies reinforce its distinctive water-repellent characteristics, and the conjugation of superoleophilicity and unparalleled hydrophobicity of a MOF material has been coherently exploited to achieve real-time oil/water separation in recyclable membrane form, with significant absorption capacity performance. This is also the first report of an oil/water separating fluorinated ultrahydrophobic MOF-based membrane material, with potential promise for tackling marine oil spillages.