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The impact of solvents on the efficiency of cationic dye adsorption from a solution onto protonated Faujasite-type zeolite (FAU-Y) was investigated in the prospect of supporting potential applications in wastewater treatment or in the preparation of building blocks for optical devices. The adsorption isotherms were experimentally determined for methylene blue (MB) and auramine O (AO) from single-component solutions in water and in ethanol. The limiting dye uptake (saturation capacity) was evaluated for each adsorption system, and it decreased in the order of MB–water > AO–water > AO–ethanol > MB–ethanol. The mutual distances and orientations of the adsorbed dye species, and their interactions with the oxygen sites of the FAU-Y framework, with the solvent molecules, and among themselves were inferred from Monte Carlo simulations and subsequently utilized to rationalize the observed differences in the saturation capacity. The dye–solvent competition and the propensity of the dyes to form compact pi-stacked dimers were shown to play an important role in establishing a non-uniform distribution of the adsorbed species throughout the porous space. The two effects appeared particularly strong in the case of the MB–water system. The necessity of including solvent effects in modeling studies is emphasized. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) possess a variety of interesting features related to their composition and structure that make them excellent candidates to be used in agriculture. However, few studies have reported their use as delivery agents of agrochemicals. In this work, the natural polyphenol chlorogenic acid (CGA) was entrapped via simple impregnation in the titanium aminoterephthalate MOF, MIL-125-NH2. A combination of experimental and computational techniques was used to understand and quantify the encapsulated CGA in MIL-125-NH2. Subsequently, CGA delivery studies were carried out in water at different pHs, showing a fast release of CGA during the first 2 h (17.3 ± 0.3% at pH = 6.5). In vivo studies were also performed against larvae of mealworm (Tenebrio molitor), evidencing the long-lasting insecticidal activity of CGA@MIL-125-NH2. This report demonstrates the potential of MOFs in the efficient release of agrochemicals, and paves the way to their study against in vivo models. [ABSTRACT FROM AUTHOR]

Cinnamic acid (CA) was successfully incorporated into Zn-Al layered double hydroxide (LDH) through coprecipitation. The CA moiety was stabilized in the interlayer space through not only electrostatic interaction but also intermolecular π-π interaction. It was noteworthy that the CA arrangement was fairly independent of the charge density of LDH, showing the important role of the layer–CA and CA-CA interactions in molecular stabilization. Computer simulations using the Monte Carlo method as well as analytical approaches including infrared, UV-vis spectroscopy, and differential scanning calorimetry showed the existence of intermolecular interaction. In order to reinforce molecular stabilization, a neutral derivative of CA, cinnamaldehyde (CAD), was additionally incorporated into LDH. It was clearly shown that CAD played a role as a π-π interaction mediator to enhance the stabilization of CA. The time-dependent release of CA from LDH was first governed by the layer charge density of LDH; however, the existence of CAD provided additional stabilization to the CA arrangement to slow down the release kinetics. [ABSTRACT FROM AUTHOR]

Adsorption isotherms of pure vapors and vapor mixtures of water, methanol, and cyclohexane were studied using a synthesized 13X zeolite (FAU topology), by means of a DVS gravimetric vapor analyzer. These results were validated by GCMC calculations. The surface chemistry of the adsorbent was characterized by the thermodesorption of ammonia, and its textural properties were studied using nitrogen physisorption. The 13X zeolite was found to be strongly acidic (BrØnsted acid sites, Si/Al = 1.3) and its specific surface area around 1100 m2·g−1. Water was found to be able to diffuse within both the supercages and the sodalite cavities of the FAU structure, whereas methanol and cyclohexane were confined in the supercages only. The water/methanol sorption selectivity of the 13X zeolite was demonstrated by co-adsorption measurements. The composition of the water/methanol adsorbed phase could be calculated by assuming IAST hypotheses. This model failed in the case of the water/cyclohexane co-adsorption system, which is in line with the non-miscibility of the components in the adsorbed state. The sorption isotherms could be successfully simulated, confirming the robustness of the forcefields used. The 13X zeolite confirmed its a priori expected hydrophilic nature, which is useful for the selective adsorption of water in a methanol–water vapor mixture. [ABSTRACT FROM AUTHOR]

Porphyrin based Metal–Organic Frameworks (MOFs) have generated high interest because of their unique combination of light absorption, electron transfer and guest adsorption/desorption properties. In this study, we expand the range of available MOF materials by focusing on the seldom studied porphyrin ligand H10TcatPP, functionalized with tetracatecholate coordinating groups. A systematic evaluation of its reactivity with M(III) cations (Al, Fe, and In) led to the synthesis and isolation of three novel MOF phases. Through a comprehensive characterization approach involving single crystal and powder synchrotron X-ray diffraction (XRD) in combination with the local information gained from spectroscopic techniques, we elucidated the structural features of the solids, which are all based on different inorganic secondary building units (SBUs). All the synthesized MOFs demonstrate an accessible porosity, with one of them presenting mesopores and the highest reported surface area to date for a porphyrin catecholate MOF (>2000 m2 g−1). Eventually, the redox activity of these solids was investigated in a half-cell vs. Li with the aim of evaluating their potential as electrode positive materials for electrochemical energy storage. One of the solids displayed reversibility during cycling at a rather high potential (∼3.4 V vs. Li+/Li), confirming the interest of redox active phenolate ligands for applications involving electron transfer. Our findings expand the library of porphyrin-based MOFs and highlight the potential of phenolate ligands for advancing the field of MOFs for energy storage materials. [ABSTRACT FROM AUTHOR]

Luminescent thermometry allows the remote detection of the temperature and holds great potential in future technological applications in which conventional systems could not operate. Complementary approaches to measuring the temperature aiming to enhance the thermal sensitivity would however represent a decisive step forward. For the first time, we demonstrate the proof‐of‐concept that luminescence thermometry could be associated with a complementary temperature readout related to a different property. Namely, we propose to take advantage of the temperature dependence of both magnetic (canonical susceptibility and relaxation time) and luminescence features (emission intensity) found in Single‐Molecule Magnets (SMM) to develop original dual magneto‐optical molecular thermometers to conciliate high‐performance SMM and Boltzmann‐type luminescence thermometry. We highlight this integrative approach to concurrent luminescent and magnetic thermometry using an air‐stable benchmark SMM [Dy(bbpen)Cl] (H2bbpen=N,N′‐bis(2‐hydroxybenzyl)‐N,N′‐bis(2‐methylpyridyl)ethyl‐enediamine)) exhibiting Dy3+ luminescence. The synergy between multiparametric magneto‐optical readouts and multiple linear regression makes possible a 10‐fold improvement in the relative thermal sensitivity of the thermometer over the whole temperature range, compared with the values obtained with the single optical or magnetic devices. [ABSTRACT FROM AUTHOR]

Layered Double Hydroxides (LDHs) are inorganic compounds of relevance to various domains, where their surface reactivity and/or intercalation capacities can be advantageously exploited for the retention/release of ionic and molecular species. In this study, we have explored specifically the applicability in the field of bone regeneration of one LDH composition, denoted "MgFeCO3", of which components are already present in vivo, so as to convey a biocompatibility character. The propensity to be used as a bone substitute depends, however, on their ability to allow the fabrication of 3D constructs able to be implanted in bone sites. In this work, we display two appealing approaches for the processing of MgFeCO3 LDH particles to prepare (i) porous 3D scaffolds by freeze-casting, involving an alginate biopolymeric matrix, and (ii) pure MgFeCO3 LDH monoliths by Spark Plasma Sintering (SPS) at low temperature. We then explored the capacity of such LDH particles or monoliths to interact quantitatively with molecular moieties/drugs in view of their local release. The experimental data were complemented by computational chemistry calculations (Monte Carlo) to examine in more detail the mineral–organic interactions at play. Finally, preliminary in vitro tests on osteoblastic MG63 cells confirmed the high biocompatible character of this LDH composition. It was confirmed that (i) thermodynamically metastable LDH could be successfully consolidated into a monolith through SPS, (ii) the LDH particles could be incorporated into a polymer matrix through freeze casting, and (iii) the LDH in the consolidated monolith could incorporate and release drug molecules in a controlled manner. In other words, our results indicate that the MgFeCO3 LDH (pyroaurite structure) may be seen as a new promising compound for the setup of bone substitute biomaterials with tailorable drug delivery capacity, including for personalized medicine. [ABSTRACT FROM AUTHOR]

We report the synthesis and structures of two base‐free alkoxide dysprosium(III) complexes of formula [Dy(L1)2(μ‐η6:η1‐Ph)2BPh2] ⋅ CH2Cl2 (1) and [Dy(L2)2(μ‐η6:η1‐Ph)2BPh2] ⋅ 3(C7H8) (2) featuring a tetraphenylborate binding (L1=2,6‐dibenzhydryl‐4‐(tert‐butyl)phenolate, L2=tri(naphtalen‐1‐yl)methanolate). Investigations of the magnetic properties for 1 in line with theoretical calculations reveal the occurrence of a field‐induced slow relaxation of the magnetization. [ABSTRACT FROM AUTHOR]

We report the synthesis, crystal structures, and magnetic and theoretical investigations of five erbium complexes based on halogenated ligands with the respective formulas trans-[Er(L1)3(THF)2] (1), trans-[Er(L2)3(Ph3PO)2] (2), fac-[Er(L3)3(THF)3] (3), fac-[Er(L4)3(Ph3PO)3] (4), and [Er(L5)3] (5) (L1 = OCPh2(CF2Cl), L2 = OCPh(CF3)2, L3 = OCH(C6F5)2, L4 = OCHMe(C6F5), L5 = 1,8-dibromo-3,6-di-tert-butylcarbazol-9-ide, THF = tetrahydrofuran). Modulation of the experimental conditions allows controlling the coordination geometry of the resulting complexes. While 1 and 2 adopt a trigonal bipyramidal geometry, 3 and 4 exhibit a distorted octahedral arrangement. In contrast, 5 exhibits a triangular coordination geometry. Magnetic investigations in line with theoretical calculations reveal that only the three-coordinated complex 5 exhibits a zero-field slow relaxation of the magnetization, while compound 1 demonstrates field-induced relaxation dynamics. [ABSTRACT FROM AUTHOR]

We report the synthesis, structures, magnetic and luminescence properties of a series of three-blade propeller homoleptic lanthanide complexes [LnL3](ClO4)3·H2O·2MeCN (Ln = Eu (1), Tb (2), Dy (3), Er (4), Yb (5), Gd (6); L = 2,6-bis(1-methyl-imidazol-2-yl)pyridine). The Eu, Tb, and Dy analogues exhibit the characteristic lanthanide-based luminescence. Remarkably, the mixed Eu/Tb complex with a metal ratio of 1 : 10 can be used as a ratiometric thermometer in the solid-state between 130 and 220 K with the maximum value of Sr = 6.6% K−1 within the range of 150–170 K. Theoretical calculations allow not only modelling of the luminescence properties of pure complexes but also rationalization of the performances of the mixed Eu/Tb thermometers. [ABSTRACT FROM AUTHOR]

In hydrolysis and electro-oxidation of the borohydride anion BH4−, key reactions in the field of energy, one critical short-living intermediate is BH3OH−. When water was used as both solvent and reactant, only BH3OH− is detected by 11B NMR. By moving away from such conditions and using DMF as solvent and water as reactant in excess, four 11B NMR quartets were observed. These signals were due to BH3-based intermediates as suggested by theoretical calculations; they were DMF·BH3, BH3OH−, and B2H7− (i.e., [H3B−H−BH3]− or [H4B−BH3]−). Our results shed light on the importance of BH3 stemming from BH4− and on its capacity as Lewis acid to interact with Lewis bases such as DMF, OH−, and BH4−. These findings are important for a better understanding at the molecular level of hydrolysis of BH4− and production of impurities in boranes synthesis. [ABSTRACT FROM AUTHOR]

We investigated a series of Mn2+-Prussian blue (PB) nanoparticles NazMnxFe1−x[Fe(CN)6]1−y□y·nH2O of similar size, surface state and cubic morphology with various amounts of Mn2+ synthesized through a one step self-assembly reaction. We demonstrated by a combined experimental–theoretical approach that during the synthesis, Mn2+ substituted Fe3+ up to a Mn/Na–Mn–Fe ratio of 32 at% in the PB structure, while for higher amounts, the Mn2[Fe(CN)6] analogue is obtained. For comparison, the post-synthetic insertion of Mn2+ in PB nanoparticles was also investigated and completed with Monte-Carlo simulations to probe the plausible adsorption sites. The photothermal conversion efficiency (η) of selected samples was determined and showed a clear dependence on the Mn2+amount with a maximum efficiency for a Mn/Na–Mn–Fe ratio of 10 at% associated with a dependence on the nanoparticle concentration. Evaluation of the in vitro photothermal properties of these nanoparticles performed on triple negative human breast adenocarcinoma (MDA-MB-231) cells by using continuous and pulsed laser irradiation confirm their excellent PTT efficiency permitting low dose use. [ABSTRACT FROM AUTHOR]

Antibiotics are found in natural waters, raising concern about their human and environmental toxicity and the wide occurrence of antibiotic resistant bacteria. The antibiotic resistance crisis is attributed to the overuse and misuse of these medications. Particularly, sulfamethazine (SMT), an antibiotic commonly used in pigs and cattle for the treatment of bacterial diseases, has been detected in the natural environment (soil and water). Among all the technologies developed to combat the deteriorating water quality and control antimicrobial resistance, heterogeneous photocatalysis should be highlighted for the degradation of refractory organic compounds. Here, we described the SMT adsorption and photodegradation capacity of a highly porous and robust zirconium-based MOF UiO-66 under realistic conditions, and its potential recyclability. Further, its SMT removal capacity was improved by functionalizing the MOF porosity (28.5% of SMT adsorption in 24 h for nanoUiO-66-NH2), and nanosizing the MOF (100% SMT photodegradation in only 4 h for nanoUiO-66). Finally, the safety of the formed by-product during SMT photodegradation was confirmed, reinforcing the potential of the application of UiO-66 in water remediation. [ABSTRACT FROM AUTHOR]

The (photo)catalytic properties of metal–organic frameworks (MOFs) can be enhanced by post-synthetic inclusion of metallic species in their porosity. Due to their extraordinarily high surface area and well defined porous structure, MOFs can be used for the stabilization of metal nanoparticles with adjustable size within their porosity. Originally, we present here an optimized ultrafast photoreduction protocol for the in situ synthesis of tiny and monodisperse silver nanoclusters (AgNCs) homogeneously supported on a photoactive porous titanium carboxylate MIL-125-NH2 MOF. The strong metal–framework interaction between –NH2 and Ag atoms influences the AgNC growth, leading to the surfactant-free efficient catalyst AgNC@MIL-125-NH2 with improved visible light absorption. The potential use of AgNC@MIL-125-NH2 was further tested in challenging applications: (i) the photodegradation of the emerging organic contaminants (EOCs) methylene blue (MB-dye) and sulfamethazine (SMT-antibiotic) in water treatment, and (ii) the catalytic hydrogenation of p-nitroaniline (4-NA) to p-phenylenediamine (PPD) with industrial interest. It is noteworthy that compared with the pristine MIL-125-NH2, the composite presents an improved catalytic activity and stability, being able to photodegrade 92% of MB in 60 min and 96% of SMT in 30 min, and transform 100% of 4-NA to PPD in 30 min. Aside from these very good results, this study describes for the first time the use of a MOF in a visible light continuous flow reactor for wastewater treatment. With only 10 mg of AgNC@MIL-125-NH2, high SMT removal efficiency over 70% is maintained after >2 h under water flow conditions found in real wastewater treatment plants, signaling a future real application of MOFs in water remediation. [ABSTRACT FROM AUTHOR]

Despite the interesting chemopreventive, antioxidant and antiangiogenic effects of the natural bioflavonoid genistein (GEN), its low aqueous solubility and bioavailability make it necessary to administer it using a suitable drug carrier system. Nanometric porous metal–organic frameworks (nanoMOFs) are appealing systems for drug delivery. Particularly, mesoporous MIL-100(Fe) possesses a variety of interesting features related to its composition and structure, which make it an excellent candidate to be used as a drug nanocarrier (highly porous, biocompatible, can be synthesized as homogenous and stable nanoparticles (NPs), etc.). In this study, GEN was entrapped via simple impregnation in MIL-100 NPs achieving remarkable drug loading (27.1 wt%). A combination of experimental and computing techniques was used to achieve a deep understanding of the encapsulation of GEN in MIL-100 nanoMOF. Subsequently, GEN delivery studies were carried out under simulated physiological conditions, showing on the whole a sustained GEN release for 3 days. Initial pharmacokinetic and biodistribution studies were also carried out upon the oral administration of the GEN@MIL-100 NPs in a mouse model, evidencing a higher bioavailability and showing that this oral nanoformulation appears to be very promising. To the best of our knowledge, the GEN-loaded MIL-100 will be the first antitumor oral formulation based on nanoMOFs studied in vivo, and paves the way to the efficient delivery of nontoxic antitumorals via a convenient oral route. [ABSTRACT FROM AUTHOR]

Spectroscopic techniques are combined with in situ pressure-controlled X-ray diffraction and molecular simulations to characterize the five-step phase transition observed upon [N.sub.2] adsorption within the high-surface area metal-organic framework Co(BDP) ([BDP).sup.2] = 1,4-benzenedipyrozolate). A weak [N.sub.2] interaction with the open [Co.sup.II] coordination sites is proposed, based on the enthalpy, for the first four phases.

The article explains the synthesis, characterization, as well as the functionalization of a series of flexible porous solids. The impact of adsorption of different liquids by these compounds on the pore opening, as well as their host-guest interactions is also discussed.

A novel microporous two-dimensional (2D) Ni-based phosphonate metal-organic framework (MOF; denoted as IEF-13) has been successfully synthesized by a simple and green hydrothermal method and fully characterized using a combination of experimental and computational techniques. Structure resolution by single-crystal X-ray diffraction reveals that IEF-13 crystallizes in the triclinic space group Pi having bi-octahedra nickel nodes and a photo/electroactive tritopic phosphonate ligand. Remarkably, this material exhibits coordinatively unsaturated nickel(II) sites, free–PO3H2 and–PO3H acidic groups, a CO2 accessible microporosity, and an exceptional thermal and chemical stability. Further, its in-deep optoelectronic characterization evidences a photoresponse suitable for photocatalysis. In this sense, the photocatalytic activity for challenging H2 generation and overall water splitting in absence of any co-catalyst using UV–Vis irradiation and simulated sunlight has been evaluated, constituting the first report for a phosphonate-MOF photocatalyst. IEF-13 is able to produce up to 2,200 µmol of H2 per gram using methanol as sacrificial agent, exhibiting stability, maintaining its crystal structure and allowing its recycling. Even more, 170 µmol of H2 per gram were produced using IEF-13 as photocatalyst in the absence of any co-catalyst for the overall water splitting, being this reaction limited by the O2 reduction. The present work opens new avenues for further optimization of the photocatalytic activity in this type of multifunctional materials. [ABSTRACT FROM AUTHOR]

A new robust Bi-carboxylate metal–organic framework (MOF) IEF-2 was hydrothermally prepared, acting as a proton carrier (σ∼ 1.1 × 10−4 S cm−1). Such proton conductivity is among the highest reported so far for purely 3D carboxylate-based MOFs, being explained by the existence of a 1D hydrogen-bond network, as suggested by structural analysis and theoretical studies. [ABSTRACT FROM AUTHOR]

Despite the higher efficiency, larger color range and faster stimulus response of polymeric electrochromic materials, their poor cyclability strongly hampers their application in optoelectronics. As an original strategy to stabilize and further nanostructure these polymers, herein an efficient encapsulation and in situ polymerization inside highly porous metal–organic frameworks (MOFs) is reported. In particular, the successful accommodation of poly(3,4-ethylendioxythiophene) (PEDOT) and its partially oxidized polarons inside the mesopores of the nontoxic iron trimesate MIL-100(Fe) is convincingly proved by a large panel of experimental techniques. Remarkably, the polymer–MOF interaction occurring for entrapped PEDOT within the pores (deeply assessed by experimental and simulation methods) might be responsible for the enhanced electrical conductivity of the resulting PEDOT@MIL-100(Fe) composite when compared to the insulating MIL-100(Fe) and the conductive free PEDOT. Furthermore, it was possible to observe the electrochromic properties of the PEDOT@MIL-100(Fe) composite, achieving an improved stability and good cyclability as a consequence of the effective protection by the MOF matrix. [ABSTRACT FROM AUTHOR]

Porous coordination polymers are molecule‐based materials presenting a high degree of tunability, which offer many advantages for targeted applications over conventional inorganic materials. This work demonstrates that the hydrophilic/hydrophobic character of Prussian blue analogues having a lipophilic feature may be tuned to optimize the gas adsorption properties. The role of the coordinatively unsaturated metal sites is emphasized through a combination of theoretical and experimental study of water, ethanol, and n‐hexane adsorption. Chemically unsaturated sites: A hydrophobic Prussian Blue analogue can be turned highly hydrophilic by pre‐adsorbing water molecules on the chemically unsaturated sites of the material. The hydrophilic/hydrophobic balance of this PBA can be finely tuned depending on the application targeted (see scheme). [ABSTRACT FROM AUTHOR]

The novel 2D bismuth–camphorate IEF‐1, formulated as [Bi(L)(HL)] (where H2L = camphoric acid), has been successfully isolated as large single crystals and easily scaled up by hydrothermal synthesis. The crystalline structure of IEF‐1 was unveiled by single‐crystal X‐ray diffraction, in the monoclinic space group P21, and fully characterized by using several standard solid‐state techniques. IEF‐1 material is thermally stable up to ca. 240 °C without any visible structural change. In addition, the study of the nonlinear optical (NLO) properties of IEF‐1 by second harmonic generation (SHG) microscopy evidenced that IEF‐1 is noncentrosymmetric and has a more intensive blue component that may be explained by the ligand to metal charge transfer behavior. [ABSTRACT FROM AUTHOR]