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Concerns regarding water contamination are escalating due to the increasing presence of all types of pollutants in water sources, which pose serious health risks to humans and wildlife, disrupt ecosystems, and compromise the safety of drinking water. Addressing water contamination requires stringent regulations and increased public awareness, but especially, it requires the development of highly effective new technologies to decontaminate those aquatic environments that have been already polluted over the past few decades. Since the emergence of metal-organic frameworks (MOFs), their use has been proposed in a multitude of fields, given their unique physicochemical properties, and one of the fields where a realistic application can be expected in the near future is water remediation. In particular, oxamidato-based biological MOFs (bioMOFs) have demonstrated, in recent years, unique properties such as extraordinary robustness, crystallinity and water- and pH-stability as well as very easy functionalisation, which situates them among the best adsorbents for this environmental purpose. In this review, we have summarised the most remarkable results of oxamidato-based bioMOFs in the field of water remediation. Moreover, on the basis of the reported results, we dare to suggest the real possibilities of application, in relevant real-world environments, for these and other MOFs, as well as the main obstacles that will need to be overcome, aiming to widening the range of applicability of MOFs and making solid headway towards sustainable development.

Since the emergence of metal-organic frameworks (MOFs), a myriad of thrilling properties and applications, in a wide range of fields, have been reported for these materials, which mainly arise from their porous nature and rich host-guest chemistry. However, other important features of MOFs that offer great potential rewards have been only barely explored. For instance, despite the fact that MOFs are suitable candidates to be used as chemical nanoreactors for the preparation, stabilization and characterization of unique functional species, that would be hardly accessible outside the functional constrained space offered by MOF channels, only very few examples have been reported so far. In particular, we outline in this feature recent advances in the use of highly robust and crystalline oxamato- and oxamidato-based MOFs as reactors for the in situ preparation of well-defined catalytically active single atom catalysts (SACS), subnanometer metal nanoclusters (SNMCs) and supramolecular coordination complexes (SCCs). The robustness of selected MOFs permits the post-synthetic (PS) in situ preparation of the desired catalytically active metal species, which can be characterised by single-crystal X-ray diffraction (SC-XRD) taking advantage of its high crystallinity. The strategy highlighted here permits the always challenging large-scale preparation of stable and well-defined SACs, SNMCs and SCCs, exhibiting outstanding catalytic activities.

Allylic alcohol epoxidation and dehydrogenation reactivity is distinguished when VO(acac) 2 is used in solution or anchored in a metal-organic framework (MOF). The chemical mechanism depends on the electronic profile of alkene substituents when the vanadyl complex is used in the homogenous phase. However, confinement effects imparted by MOF channels allow gaining control of the chemoselectivity toward the dehydrogenation product.

Here we show that a structure containing a polymeric interlocking daisy chain is obtained from the reaction of an inorganic-organic [2]rotaxane [HB{CrIII7NiII(μ-F)8(O2CtBu)16}], where B is an organic thread terminated with a bi-pyridyl unit, with an oxo-centered metal carboxylate triangle [FeIII2CoII(μ3-O)(O2CtBu)6(HO2CtBu)3].

We report the application of a post-synthetic solid-state cation-exchange process to afford a novel 3D MOF with hydrated barium cations hosted at pores able to trigger selective and reversible SO 2 adsorption. Computational modelling supports the full reversibility of the adsorption process on the basis of weak supramolecular interactions between SO 2 and coordinated water molecules.

The solid-state incorporation of a mononuclear iron(iii) complex within the pores of a magnetic 3D metal-organic framework (MOF) in a single crystal to single crystal process leads to the formation of a new hybrid material showing both a guest-dependent long-range magnetic ordering and a spin-crossover (SCO) behaviour.

Triple-stranded dinuclear nickel(ii) complexes of the meso-helicate type have been obtained from the new N,N'-1,3-phenylenebis(pyrazine-2-carboxamidate) ligand; they possess a multielectron redox behaviour featuring up to four stepwise, one-electron oxidation reactions of the two ferromagnetically coupled Ni(II) ions to afford the putative high-valent dinickel(iii) and dinickel(iv) species, as supported by theoretical calculations.

The design and synthesis of novel examples of multifunctional magnetic materials based on the so-called coordination polymers (CPs) have become very attractive for chemists and physicists due to their potential applications in nanoscience and nanotechnology. However, their preparation is still an experimental challenge, which requires a deep knowledge of coordination chemistry and large skills in organic chemistry. The recent advances in this field using a molecular-programmed approach based on rational self-assembly methods which fully exploit the versatility of the coordination chemistry of the barely explored and evergreen family of N-substituted aromatic oligo(oxamato) ligands are presented in this feature article. These exploratory studies have revealed a wide variety of interesting multifunctional magnetic materials such as optically-active chiral and luminescent magnets or dynamic porous magnets as candidates for chemical sensing. Our feeling, however, is that we have only scratched the surface of the topic and that there are many more exciting brand-new molecule-based materials waiting to be discovered.

The Cu(2+)-mediated self-assembly of oxamato-based ligands derived from either the (S)- or (R)-enantiomers of the amino acid valine leads to the formation of two antiferromagnetically coupled homochiral anionic hexacopper(II) wheels in the presence of templating tetramethylammonium countercations.

A unique magnetic electroswitching behavior has been observed in an oxamato-based permethylated dicopper(II) paracyclophane; upon reversible one-electron oxidation of the double tetramethyl-substituted p-phenylenediamidate bridging skeleton, the spin alignment of the two Cu(II) ions (S(Cu) = ½) changes from antiparallel (OFF) to parallel (ON) in the resulting dicopper(II) π-radical cation species.

Increasing dimensionality [from 2D (1) to 3D (2)] and T(C) [from 10 (1) to 20 K (2)] in two new oxamato-bridged heterobimetallic Mn(II)(2)Cu(II)(3) open-frameworks result from the steric hindrance provided by the different alkyl substituents of the N-phenyloxamate bridging ligands., (This journal is © The Royal Society of Chemistry 2012)

Thermally reversible photomagnetic (ON/OFF) switching behavior has been observed in a dinuclear oxamatocopper(II) anthracenophane upon UV light irradiation and heating; the two Cu(II) ions (S(Cu) = 1/2) that are antiferromagnetically coupled in the dicopper(II) metallacyclic precursor (ON state) become uncoupled in the corresponding [4+4] photocycloaddition product (OFF state), as substantiated from both experimental and theoretical studies.