Having access to clean water is a mandatory requirement for the proper development of living beings.

We report a new water-stable multivariate (MTV) metal–organic framework (MOF) prepared by combining two different oxamide-based metalloligands derived from the natural amino acids l-serine and l-methionine. This unique material features hexagonal channels decorated with two types of flexible and functional “arms” (−CH2OH and −CH2CH2SCH3) capable of enabling, synergistically, the simultaneous and efficient removal of both inorganic (heavy metals such as Hg2+, Pb2+, and Tl+) and organic (dyes such as Pyronin Y, Auramine O, Brilliant green, and Methylene blue) contaminants, and, in addition, this MTV-MOF is completely reusable. Single-crystal X-ray diffraction measurements allowed solving the crystal structure of a host–guest adsorbate, containing both HgCl2 and Methylene blue, and offered unprecedented snapshots of this unique dual capture process. This is the very first time that a MOF can be used for the removal of all sorts of pollutants from water resources, thus opening new perspectives for this emerging type of MTV-MOF.

We report a novel highly crystalline MOF, featuring hydroxyl-decorated channels, capable of distinctly organizing guest organic molecules within its pores.

Ferroelectrics (FEs) are materials of paramount importance with a wide diversity of applications. Herein, we propose a postsynthetic methodology for the smart implementation of ferroelectricity in chiral metal-organic frameworks (MOFs): following a single-crystal to single-crystal cation metathesis, the Ca counterions of a preformed chiral MOF of formula Ca{Cu[(S,S)-hismox](OH)}·212HO (1), where hismox is a chiral ligand derived from the natural amino acid l-histidine, are replaced by CHNH. The resulting compound, (CHNH){Cu[(S,S)-hismox](OH)}·178HO (2), retains the polar space group of 1 and is ferroelectric below 260 K. These results open a new synthetic avenue to enlarge the limited number of FE MOFs.

The mercury removal efficiency of a novel metal‐organic framework (MOF) derived from the amino acid S‐methyl‐L‐cysteine is presented and the process is characterized by single‐crystal X‐ray crystallography. A feasibility study is further presented on the performance of this MOF—and also that of another MOF derived from the amino acid L‐methionine—when used as the sorbent in mixed matrix membranes (MMMs). These MOF‐based MMMs exhibit high efficiency and selectivity—in both static and dynamic regimes—in the removal of Hg2+ from aqueous environments, due to the high density of thioalkyl groups decorating MOF channels. Both MMMs are capable to reduce different concentration of the pollutant to acceptable limits for drinking water (<2 parts per billion). In addition, a novel device, consisting of the recirculation and adsorption of contaminated solutions through the MOF–MMMs, is designed and successfully explored in the selective capture of Hg2+. Thus, filtration of Hg2+ solutions with multiple passes through the permeation cell shows a gradual decrease of the pollutant concentration. These results suggest that MOF‐based MMMs can be implemented in water remediation, helping to reduce either contaminants from accidental unauthorized or deliberate metal industrial dumping and to ensure access for clean and potable freshwater.