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This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemistry of Materials, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/cm070553+ ; [EN] Layered organic-inorganic hybrid materials were synthesized by pillaring with viologen and nitroaniline compounds which are intercalated between magadiite layers. The bridged silsesquioxanes, 4,4'-bis(trimethoxysilylpropyl)viologen and 4-nitro-N,N'-bis(3-trimethoxysilyl)propylaniline react with the surface silanol groups of the inorganic layers of silicate, bonding covalently with them. The preparation process was followed by DRX, and the pillarization was corroborated using chemical and thermogravimetrical analyses. The presence of viologen and nitroaniline organic linkers covalently bonded to inorganic layers was confirmed by C-13 and Si-29 NMR spectroscopy. UV-visible diffuse reflectance permitted to observe the high stabilization achieved by the intercalated organic fragments. Micro- and mesoporosity were also generated because of the existence of interlayer galleries conformed by homogenously distributed organic linkers into the interlayer space. The layered organic-inorganic hybrids exhibited a thermally stable network, and the organic spacers remained after elimination of the swelling agents by acid extraction. The resultant materials can be of interest as sensors and for nonlinear optics. ; Financial support by the Spanish Government (MAT-2006-14274-C02-01 and MAT2006-26599-E) and Universidad Polite´cnica de Valencia (PPI-06-05) is gratefully acknowledged. ; Díaz Morales, UM.; Cantin Sanz, A.; Corma Canós, A. (2007). Novel layered organic-inorganic hybrid materirals with bridged silsesquioxanes as Pillars. Chemistry of Materials. 19(15):3686-3693. https://doi.org/10.1021/cm070553+ ; S ; 3686 ; 3693 ; 19 ; 15

Four commercially available, cost-effective ion exchange membranes (two cationic and two anionic exchange membranes, CEMs and AEMs, respectively) were modified to mitigate crossover phenomena of the redox active species typically observed in Aqueous Organic Redox Flow Batteries (AORFB) systems. The modification strategy was carried out using a pyrrole(Py)-based polymer which successfully reduced the permeation of two redox active organic molecules, a viologen derivative (named BP7 throughout this study) and TEMPOL, by an order of magnitude. Additionally, modified membranes showed not significant changes in ion conductivity, with negligible effect on the electrical conductivity of the membranes at a given conditions. The morphology, physicochemical, mechanical, and electrochemical properties of the membranes were determined to evaluate the impact of these modifications. AEMs modified in this manner were found to have optimal properties, showing an increase in ion exchange capacity while maintaining excellent mechanical stability and unaltered permselectivity. Additionally, the diffusion boundary layer of these AEMs was slightly extended, which suggests a greater double layer stability for ion exchange processes than in the case of CEMs. Our work shows that these modified membranes could be an appealing approach for AORFB applications ; This work has been funded by the European Union under the HIGREEW project, Affordable High-performance Green Redox Flow batteries (Grant agreement no. 875613). H2020: LC-BAT-4-2019875613)

The use of Metal–Organic Frameworks as crystalline matrices for the synthesis of multiple component or multivariate solids by the combination of different linkers into a single material has emerged as a versatile route to tailor the properties of single-component phases or even access new functions. This approach is particularly relevant for Zr6-MOFs due to the synthetic flexibility of this inorganic node. However, the majority of materials are isolated as polycrystalline solids, which are not ideal to decipher the spatial arrangement of parent and exchanged linkers for the formation of homogeneous structures or heterogeneous domains across the solid. Here we use high-throughput methodologies to optimize the synthesis of single crystals of UiO-68 and UiO-68-TZDC, a photoactive analogue based on a tetrazine dicarboxylic derivative. The analysis of the single linker phases reveals the necessity of combining both linkers to produce multivariate frameworks that combine efficient light sensitization, chemical stability, and porosity, all relevant to photocatalysis. We use solvent-assisted linker exchange reactions to produce a family of UiO-68-TZDC% binary frameworks, which respect the integrity and morphology of the original crystals. Our results suggest that the concentration of TZDC in solution and the reaction time control the distribution of this linker in the sibling crystals for a uniform mixture or the formation of core–shell domains. We also demonstrate how the possibility of generating an asymmetric distribution of both linkers has a negligible effect on the electronic structure and optical band gap of the solids but controls their performance for drastic changes in the photocatalytic activity toward proton or methyl viologen reduction. ; Financial support for this work was provided by the Marie Skłodowska-Curie Global Fellowships (749359-EnanSET, N.M.P) within the European Union research and innovation framework programme (2014-2020)

[Note: See PDF for correct symbols.] Perchlorate (ClO4-) is an important energetic component of solid rocket fuel. The major source of ClO4- pollution is the military, space program and supporting industries. ClO4- is recalcitrant in the environment and is potentially toxic. The California Department of Health Services adopted an action level of 4 ppb for perchlorate in potable water. Microorganisms that reduce ClO4- to chloride and molecular oxygen have been isolated. For designing an efficient biological-based ground water ClO4- remediation strategy, the biochemical and molecular data on the enzymatic reduction of ClO4- are needed. The ClO4- respiring organism, perc1ace when grown using either ClO4- or NO3- as a terminal electron acceptor produced ClO4- reductase to a significant extent. The ClO4- reductase activity appeared to be within the periplasmic space, with activities as high as 14, 000 nmol-1 min-1 mg protein-1, indicating that it is a soluble enzyme. A ClO4- reductase from cell-free extracts of perc1ace was purified 10-fold by ion-exchange and molecular exclusion fast protein liquid chromatography (FPLC). The ClO4- reductase catalyzed the reduction of ClO4- at a Vmax and Km of 4.8 Units mg protein-1 and 34.5 M, respectively. Maximal activity was recorded at 25-30oC and pH 7.5 – 8.0. Perc1ace ClO4- reductase is a dimer with molecular masses of 35.07 kDa and 75.1 kDa determined by SDS-PAGE. Matrix-Assisted Laser Desorption Ionization-Time of Flight/Mass Spectrometry (MALDI-TOF/MS) analysis of the 35 kDa protein revealed several tryptic peptides. To study the genetic determinants of ClO4- reductase, the amino terminal sequences of 22 tryptic peptides of the approximately 35 kDa ClO4- reductase subunit were obtained by electrospray mass spectrometry. GenBank Blast analysis of the amino acid sequences revealed similarity to reductases, dehydrogenases and heme proteins. In batch studies of in vitro reduction of perchlorate, perc1ace ClO4- reductase reduced perchlorate in water with either NADH or methyl viologen as an electron donor. Less enzyme activity was observed with methanol and ethanol. Experiments showed that ClO4- reductase immobilized to Ca alginate reduced ClO4-. Additional studies are focusing on optimization of reaction conditions for perchlorate reduction by immobilized perchlorate reductases, molecular characterization of the overall genetic determinants of ClO4- bioreduction by perc1ace by cloning the genes using degenerate primers designed from the amino acid sequences of ClO4- reductase tryptic peptides and over-expression of recombinant ClO4- reductase. Such a recombinant enzyme available in large quantities can be immobilized and safely used for the treatment of perchlorate contaminated ground water on site. Treatment systems designed to employ cell-free enzymes catalyze the ClO4- reduction reaction without the production of biomass wastes. Moreover, the spent enzymes can be regenerated and reused, substantially reducing cost.