Reverse osmosis and nanofiltration membranes for highly efficient PFASs removal: overview, challenges and future perspectives

Today, it is extremely urgent to face the increasing shortage of clean and safe water resources, determined by the exponential growth of both world population and its consumerism, climate change and pollution. Water remediation from traditional chemicals and Contaminants of Emerging Concerns (CECs) is supposed to be among the major methods to solve water scarcity issues. Reverse Osmosis (RO) and Nanofiltration (NF) membrane separation technologies have proven to be feasible, sustainable and highly effective methods for the removal of contaminants, comprising the extremely persistent and recalcitrant perfluoroalkyl substances (PFASs), which failed to be treated through the traditional water treatment approaches. So far, however, they have been unable to assure PFASs levels under the established guidance limits for drinking water and still suffer from fouling problems, which limit their large-scale application. Novel configurations, improvement in process design and the development of high-performant materials for membrane production are important steps to tackle these issues, especially in view of new more stringent regulations limiting PFASs content in drinking water. As a possible future strategy, nanocomposite Mixed Matrix Membranes (MMMs) offer a platform of advanced materials which promise to revolutionize RO/NF technology for water treatment. In particular, the introduction of MOFs as adsorbent fillers in the polymeric membrane matrix appears as a viable approach for the effective and selective capture and removal of PFASs from water. The objective of this review is to provide a dedicated outlook on the most recent advances in RO and NF membrane technologies for PFASs removal. The effects of membrane properties, the solution chemistry, and contaminant properties on the RO/NF performances will be discussed in detail. Future challenges are also discussed, offering new perspectives toward the development of new advanced membranes with improved performance for PFAS removal, which are likely to significantly progress RO and NF technology for water remediation

Synthesis of a rod-based porous coordination polymer from a nucleotide as a sequential chiral inductor

We report the two-step synthesis of a novel chiral rod-based porous coordination polymer (PCP). The chemical approach consists on the use of a previously prepared bis(ethylendiamine) copper monomer of formula [Cu(en)]2(NO3)2 [where en = ethylendiamine] reacting with the cytidine 5'-monophosphate (CMP) nucleotide. The bis(ethylendiamine) copper compound -stabilized by the axial coordination of nitrate counter-anions- reacts in the presence of sodium salt of CMP to yield right-handed copper(II) chains of P helicity with formula [Cu2(en)2(CMP)2] . 5H2O (1). The axial coordination of the CMP2- ligands through the N3 and O2 sites (free nitrogen and carbonyl groups) of the cytosine nucleobase and oxygen atoms of phosphate moieties, ensure the stabilization of the neutral chiral polymer. The supramolecular organization involves strong hydrogen bonding interactions to build supramolecular chains of the same helicity. The resulting PCP constitutes one of the few examples of CMP compounds exhibiting a such coordination involving both nucleobase and phosphate moieties, where a highly stable metal complex is used as precursor for the rational construction of rod-based hydrogen metal-organic frameworks (HMOFs). Furthermore, it is underlined the intrinsic capability of biomolecules to act as chiral transfer systems

A novel supramolecular assembly in an iron(III) compound exhibiting magnetic ordering at 70 K

Ethyl-substituted ammonium cation allows the preparation of an unprecedented oxo- and oxalato-bridged supramolecular three-dimensional network. The compound exhibits magnetic ordering with Tc = 70 K due to a weak spin canting.Julve Olcina, Miguel, [email protected] ; Lloret Pastor, Francisco, [email protected]

Crystallographic Visualization of a Double Water Molecule Addition on a Pt-1-MOF during the Low-temperature Water-Gas Shift Reaction

This is the peer reviewed version of the following article: C. Bilanin, E. Tiburcio, J. Ferrando-Soria, D. Armentano, A. Leyva-Pérez, E. Pardo, ChemCatChem 2021, 13, 1195, which has been published in final form at https://doi.org/10.1002/cctc.202001492. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] The low-temperature water-gas shift reaction (WGSR, CO+H2O H-2+CO2) is considered a very promising reaction -candidate for fuel cells- despite an efficient and robust catalyst is still desirable. One of the more prominent catalysts for this reaction is based on single Pt atoms (Pt-1) on different supports, which are supposed to manifold the reaction by the accepted mechanism for the general WGSR, i. e. by addition of one H2O molecule to CO, with generation of CO2 and H-2. Here we show, experimentally, that not one but two H2O molecules are added to CO on the Pt-1 catalyst, as assessed by a combination of reactivity experiments with soluble Pt catalysts, kinetic and spectroscopic measurements, and finally by in-operando single crystal X-ray diffraction on a Pt-1-MOF, to visualize the formation of the hemiacetal intermediate on the solid catalytic site. These results confirm our previous DFT predictions and provide a paradigmatic shift in the assumed mechanism of the WGSR, which may open the debate if two H2O molecules are recurrently added during the WGSR, not only for Pt-1 catalysts but also for other metal catalysts.This work was supported by the Ministero dell'Istruzione, dell'Universita e della Ricerca (Italy) and the Ministerio de Ciencia e Innovacion (Spain) (Projects PID2019-104778GB-I00 and CTQ2017-86735-P and the excellence units "Severo Ochoa" SEV-2016-0683 and "Maria de Maeztu" CEX2019-000919-M). C. B. and E. T. thank ITQ and MINECO for the concession of fellowships. Thanks are extended to the "2019 Post-doctoral Junior Leader-Retaining Fellowship, la Caixa Foundation (ID100010434 and fellowship code LCF/BQ/PR19/11700011" (J. F.-S.). D.A. acknowledges the financial support of the Fondazione CARIPLO / "Economia Circolare: ricerca per un futuro sostenibile" 2019, Grant number: 2019-2090, MOCA. We thank to Dr. R. Adam, Dr. J. Oliver-Meseguer and J. C. Arango for their help. E.P. acknowledges the financial support of the European Research Council under the European Union's Horizon 2020 research and innovation programme / ERC Grant Agreement No 814804, MOF-reactors. We acknowledge Diamond Light Source for awarded beamtime and provision of synchrotron radiation facilities with dosing gas cell and thank Dr Mark Warren for his assistance at I19 beamline (Proposal number MT18768-2).Bilanin-Artigado, C.; Tiburcio, E.; Ferrando-Soria, J.; Armentano, D.; Leyva Perez, A.; Pardo, E. (2021). Crystallographic Visualization of a Double Water Molecule Addition on a Pt-1-MOF during the Low-temperature Water-Gas Shift Reaction. ChemCatChem. 13(4):1195-1200. https://doi.org/10.1002/cctc.202001492S1195120013

Magnetic order in a CuII-DyIII oxamato-based two-dimensional coordination polymer

We report the synthesis, crystal structure and magnetic characterization of a novel two-dimensional copper(II)-dysprosium(III) coordination polymer of formula [LiI(OH2)4]2[DyIIICuII2(Me2pma)4Cl(H2O)] . 4H2O (1) [Me2pma = N-2,6-dimethylphenyloxamate]. Compound 1 was obtained by using the mononuclear anionic complex, [CuII(Me2pma)2]2-, as a bis(bidentate) metalloligand toward solvated dysprosium(III) cations and shows a square [DyIIICuII2] layered structure of (44.62) net topology. Interestingly, the combination of two factors, the well-known efficiency of oxamato ligands to transmit strong magnetic couplings between neighboring atoms and such structural topology, is responsible for the observation of a ferromagnetic interaction between copper(II) and dysprosium(III) cations and a magnetic ordering (TC = 7.5 K), paving the way for the obtention of novel future examples of the still very scarce magnetically ordered lanthanide-based coordination polymers

Stabilized Ru[(H2O)(6)](3+) in Confined Spaces (MOFs and Zeolites) Catalyzes the lmination of Primary Alcohols under Atmospheric Conditions with Wide Scope

[EN] Imines are ubiquitous intermediates in organic synthesis, and the metal-mediated imination of alcohols is one of the most direct and simple methods for their synthesis. However, reported protocols lack compatibility with many other functional groups since basic supports/media, pure oxygen atmospheres, and/or released hydrogen gas are required during reaction. Here we show that, in contrast to previous metal-catalyzed methods, hexa-aqueous Ru(III) catalyzes the imination of primary alcohols with very wide functional group tolerance, at slightly acid pH and under low oxygen atmospheres. The inorganic metal complex can be supported and stabilized, integrally, within either faujasite-type zeolites (Y and X) or a metal organic framework (MOF), to give a reusable heterogeneous catalyst which provides an industrially viable process well below the flammability limit of alcohols and amines.This work was supported by the MINECO (Spain) (Projects CTQ2017-86735-P, CTQ2016-75671-P, CTQ2014-56312-P, CTQ2014-55178-R, and MAT2013-40823-R and Excellence Units "Severo Ochoa" SEV2016-0683 and "Maria de Maeztu" and MDM-2015-0538) and the European Union through ERC-AdG-2014-671093 (SynCatMatch) and the Ministero dell'Istruzione, dell'Universita e della Ricerca (Italy) (FFABR 2017). M.M. thanks the MINECO for a predoctoral contract. RA. thanks UPV for a postdoctoral contract. J.F.-S. acknowledges financial support from the Subprograma Atraccio de Talent - Contractes Postdoctorals de la Universitat de Valencia. We also acknowledge SOLEIL for provision of the synchrotron radiation facility and thank Pierre Fertey for his assistance.Mon, M.; Adam-Ortiz, R.; Ferrando-Soria, J.; Corma Canós, A.; Pardo, E.; Armentano, D.; Leyva Perez, A. (2018). Stabilized Ru[(H2O)(6)](3+) in Confined Spaces (MOFs and Zeolites) Catalyzes the lmination of Primary Alcohols under Atmospheric Conditions with Wide Scope. ACS Catalysis. 8(11):10401-10406. https://doi.org/10.1021/acscatal.8b03228S104011040681

Glassy PEEK‐WC vs Rubbery Pebax®1657 Polymers: Effect on the Gas Transport in CuNi‐MOF Based Mixed Matrix Membranes

Mixed matrix membranes (MMMs) are seen as promising candidates to overcome the fundamental limit of polymeric membranes, known as the so‐called Robeson upper bound, which defines the best compromise between permeability and selectivity of neat polymeric membranes. To overcome this limit, the permeability of the filler particles in the MMM must be carefully matched with that of the polymer matrix. The present work shows that it is not sufficient to match only the permeability of the polymer and the dispersed phase, but that one should consider also the individual contributions of the diffusivity and the solubility of the gas in both components. Here we compare the gas transport performance of two different MMMs, containing the metal-organic framework CuNi‐MOF in the rubbery Pebax®1657 and in the glassy poly(ether‐ether‐ketone) with cardo moiety, PEEK‐WC. The chemical and structural properties of MMMs were investigated by means of FT‐IR spectroscopy, scanning electron microscopy and EDX analysis. The influence of MOF on the mechanical and thermal properties of both polymers was investigated by tensile tests and differential scanning calorimetry, respectively. The MOF loading in Pebax®1657 increased the ideal H2/N2 selectivity from 6 to 8 thanks to an increased H2 permeability. In general, the MOF had little effect on the Pebax®165 membranes because an increase in gas solubility was neutralized by an equivalent decrease in effective diffusivity. Instead, the addition of MOF to PEEK‐WC increases the ideal CO2/CH4 selectivity from 30 to ~48 thanks to an increased CO2 permeability (from 6 to 48 Barrer). The increase in CO2 permeability and CO2/CH4 selectivity is maintained under mixed gas conditions

Highly Efficient MOF-Driven Silver Subnanometer Clusters for the Catalytic Buchner Ring Expansion Reaction

[EN] The preparation of novel efficient catalyststhat could be applicable in industrially important chemical processeshas attracted great interest. Small subnanometer metal clusters can exhibit outstanding catalytic capabilities, and thus, research efforts have been devoted, recently, to synthesize novel catalysts bearing such active sites. Here, we report the gram-scale preparation of Ag-2(0) subnanometer clusters within the channels of a highly crystalline three-dimensional anionic metal-organic framework, with the formula [Ag-2(0)]@(Ag2Na2I)-Na-I{Ni-4(II)[Cu-2(II)(Me(3)mpba)(2)](3)}middot48H(2)O [Me(3)mpba(4-) = N,N '-2,4,6-trimethyl-1,3-phenylenebis(oxamate)]. The resulting crystalline solid catalystfully characterized with the help of single-crystal X-ray diffractionexhibits high catalytic activity for the catalytic Buchner ring expansion reaction.This work was supported by the Ministero dell'Universita e della Ricerca (Italy), the MICIIN (Spain) (projects PID2020- 115100GB-I00, PID2019-104778GB-I00 and Excellence Unit "Maria de Maeztu" CEX2019-000919-M) , and the Generalitat Valenciana (project PROMETEO/2021/054). Thanks are also extended to the Ramon y Cajal Program (RYC2019-027940-I) (J. F.-S.) and the Diamond Light Source for the awarded beamtime and provision of synchrotron radiation facilities (proposal no. CY22411-1). We particularly acknowledge Dr David Allan and Sarah Barnett for their assistance at the I19 beamline. E.P. acknowledges the financial support of the European Research Council under the European Union's Horizon 2020 research and innovation programme/ERC grant agreement no 814804, MOF-reactors. M.M. thanks MICIIN from a contract under the Juan de la Cierva program (FJC2019-040523-I). Y.Z. thanks the China Scholarship Council (CSC no: 202009350009) for a Ph.D. fellowship.Tiburcio, E.; Zheng, Y.; Mon-Conejero, M.; Martín, N.; Ferrando-Soria, J.; Armentano, D.; Leyva Perez, A.... (2022). Highly Efficient MOF-Driven Silver Subnanometer Clusters for the Catalytic Buchner Ring Expansion Reaction. Inorganic Chemistry. 61:11796-11802. https://doi.org/10.1021/acs.inorgchem.2c0150811796118026

Enhancement of the Intermolecular Magnetic Exchange through Halogen···Halogen interactions in Bisadeninium Rhenium(IV) Salts

Two novel Re^IV salts of general formula [H₂ade]₂[Re^IVX₆]­X₂·4H₂O [H₂ade²⁺ = 9<i>H</i>-adenine-1,7-diium; X = Cl­(<b>1</b>) and Br­(<b>2</b>)] have been synthesized and magnetostructurally characterized. <b>1</b> and <b>2</b> are isostructural salts that crystallize in the orthorhombic system with space group <i>Fdd</i>2. Both compounds are made up of discrete mononuclear [Re^IVX₆]^2– and X^– anions and doubly protonated adenine cations. The six-coordinate rhenium­(IV) ion is bonded to six halide ligands [X = Cl (<b>1</b>) and Br (<b>2</b>)] in an octahedral geometry. Short intermolecular Re^IV–X···X–Re^IV interactions, as well as Re^IV–X···H–N­(H₂ade) and Re^IV–X···H–O_w hydrogen bonds, are present in the crystal lattice of <b>1</b> and <b>2</b>. Magnetic susceptibility measurements on polycrystalline samples of <b>1</b> and <b>2</b> in the temperature range 2.0–300 K show the occurrence of significant intermolecular antiferromagnetic interactions in both compounds, resulting in the observation of maxima in χ_M at ca. 6.0 (<b>1</b>) and 12.0 K (<b>2</b>). The larger spin delocalization from the Re^IV ion onto the peripheral bromide ligands when compared to the chloride ligands accounts for the enhancement of the magnetic exchange observed in <b>2</b>