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A new catalyst has been synthesized from the precursor [Pd2{μ-(C6H4) PPh2}2 {μ-O2C(C6H5)}2] immobilized on a carboxypolystyrene polymer that exhibits an excellent dispersion of the Pd (II) centers, reusability, and catalytic activity in front of phenyl bromides. The activity of this new material was studied in detail for the Suzuki-Miyaura reaction and compared to that of Pd nanoparticles (NPs) supported on UVM-7 (a mesoporous silica), and Pd NPs stabilized with polyvinylpirrolydone. The homogeneous/heterogeneous character of the catalytic process was determined from the results of the hot-filtration, centrifugation, poisoning, three phases tests, and from differential sensitivity kinetic assays. Changes in the palladium oxidation state, and the size and morphology of the Pd NPs formed during several reusing catalytic cycles were determined by XPS, and by SEM and STEM-HAADF respectively. Kinetic and structural analyses concluded that the new material behaved as a supplier of active Pd(0) NPs to the Suzuki-Miyaura catalytic cycle, which was determined to be driven mainly by the palladium fraction present in solution.

[EN] We report herein an evaluation of the effect of several mesoporous silica nanoparticles (MSNs) on the cellular uptake and in vitro cytotoxicity in human cells. Bare MSNs and MSNs functionalized with polyethylene glycol or hyaluronic acid are employed to evaluate uptake efficiency and mechanisms of endocytosis in cancer (MDA-MB-231) and non-cancer (MCF10A) cells. Moreover, changes in viability, cell cycle, oxidative stress, and mitochondrial membrane potential are evaluated. Our results confirm that MSNs are internalized efficiently by human cells and that uptake mechanisms differ for cell types and particles. We also confirm that MSNs are biocompatible materials that do not induce ROS/RNS production, nor changes on mitochondrial membrane potential or cell cycle., The authors want to thank the Spanish Government RTI2018-100910-B-C41 (MCUI/AEI/FEDER, UE) and PI18/01219 (ISCIII), the Generalitat Valenciana (PROMETEO/2018/024 and ACIF/2016/030), and CIBER-BBN (CB07/01/2012) and CIBER-ONC (CB16/12/00481) for support.

[EN] A new Pd(0) catalyst supported on silica UVM-7 has been synthesized from the organometallic [Pd-2(mu-(C6H4) Pp(2))(2)(CH3CN)(4)](BF4)(2) precursor, characterized by the high dispersion, activity, and small size of the palladium nanoclusters fixed on the silica surface. The catalyst was tested for the Suzuki-Miyaura (SM) reaction of different 4-substitutedphenyl halides with phenylboronic acid. The kinetic study concurs with most of the catalytic action was carried out by Pd species originated by the partial solubilization of Pd immobilized on mesoporous silica. The Schmidt's analysis of differential selectivity (SADS) in several competitive SM reactions, together the STEM-HAADF and HRTEM images of the catalyst surface taken along several reuse cycles support the conclusions of the kinetic study. Furthermore, this hypothesis was critically investigated using different classic approaches to distinguish between homogeneous and heterogeneous catalysis as the three phases test, poisoning, and hot filtrate experiments. (C) 2018 Elsevier Inc. All rights reserved., We thank the Spanish Ministerio de Economía y Competitividad and European Feder Funds (MAT2015-64139-C4-2-R) for funding this research.

Due to the narrowrange between boron necessities and toxicity in the environment, there is a high interest in the design of effective boron remediation procedures. We have previously reported a promising boron adsorptionmaterial based on the affinity of boron aqueous species for cis-diol groups that were anchored on differentmesoporous silica matrices.However, the small particle size of these systemsmakes themdifficult to be applied on real remediation situations. In this context we report herein a novel systemfor boron adsorption fromaqueous solutions inwhich the high boron affinity for functionalized mesoporousmaterials is combined with themechanical properties of ceramic foams as macroscopic supports. The efficiency of these new composites for boron removal is very high and comparable with the parent microparticulated adsorbent., Financial support from the Spanish Government (Project MAT2009-14564-C04-01 and MAT2009-14564-C04-04, and MAT2012-38429-C04-01 and MAT2012-38429-C04-02) and the Generalitat Valenciana (Project PROMETEO/2009/016) is gratefully acknowledged. C.S. thanks the MICINN for a predoctoral fellowship.

ω-VOPO 4 has been prepared by thermal decomposition of different oxovanadium hydrogen phosphates, namely VO(HPO 4 ) n H 2 O ( n =2( α ), 2(β) and 4) and β-NH 4 (VO 2 )(HPO 4 ). The ω-VOPO 4 phase only remains well crystallised at relatively high temperatures. Its crystal structure has been determined ab initio from X-ray powder diffraction data collected at 475°C. The cell is tetragonal (space group P4 2 /mmc) with a =4.8552(3) A and c =8.4301(6) A. Starting positional parameters were obtained by direct methods, and the structure was refined using Rietveld profile refinement principles. Disorder of two oxygen sublattices is observed. To rationalise some features of the crystal structure of this new phase, a dynamic model is proposed and discussed.

We describe here for the first time the surfactant-assisted synthesis of thermally stable mesoporous pure TiO 2 having a high surface area. Our synthetic approach to the chemistry of this system is based on the equilibrium between the hydrolysis and condensation reactions of the inorganic species and the organic–inorganic self-assembling processes. The use of titanatrane complexes helps to retard the hydrolysis and condensation reactions, thus allowing us to overcome the difficulties in preparing titanium dioxide mesoporous materials starting from highly reactive Ti-alkoxides. The mesoporous material has been characterized by TEM, XRD and N 2 adsorption–desorption isotherms and displays a typical wormhole-like pore structure.

A new simple and versatile technique to obtain mesoporous oxides is presented. While implying surfactant-assisted formation of mesostructured intermediates, the original chemical contribution of this approach lies in the use of atrane complexes as precursors. Without prejudice to their inherent unstability in aqueous solution, the atranes show a marked inertness towards hydrolysis. Bringing kinetic factors into play, it becomes possible to control the processes involved in the formation of the surfactant–inorganic phase composite micelles, which constitute the elemental building blocks of the mesostructures. Independent of the starting compositional complexity, both the mesostructured intermediates and the final mesoporous materials are chemically homogeneous. The final ordered mesoporous materials are thermally stable and show unimodal porosity, as well as homogeneous microstructure and texture. Examples of materials synthesised on account of the versatility of this new method, including siliceous, non siliceous and mixed oxides, are presented and discussed.

On the basis of the industrial interest of the oxovanadium phosphate catalysts, current research effort in this field is focused mainly on the development of synthetic strategies directed towards obtaining open-framework materials. There is a growing body of work describing preparations using hydrothermal procedures under a diversity of conditions. A great number of new solids, whose nets range from lamellar arrays to micro- and mesostructured organizations, has been prepared in last years. In this context, the applicability of concepts and procedures from the zeolites chemistry to systems involving transition elements is critically analyzed.

The dumortierite-family structuresM12X2(SeO3)8(OH)6(M= Co2+and Ni2+;X= OH−and F−) have been synthesized. The crystal structures of the hydroxo-derivatives have been refined from X?ray powder diffraction data in the space groupP63mc(Z= 1) witha= 12.887(3) A andc= 4.981(4) A (M= Co2+,X= OH−or F−) anda= 12.704(5) A andc= 4.925(6) A (M= Ni2+,X= OH−or F−). Application of the Partial Charge Transference Model allows the understanding of the selenite derivatives crystal chemistry.

Ferrocenecarboxaldehyde reacts with 2-amino-benzoic acid, 2-amino-5-methyl-benzoic acid or 3-amino-2-naphthoic acid to give the corresponding Schiff-base derivatives 2-ferrocenylmethylidenimino-benzoic acid (1), 2-ferrocenylmethylidenimino-5-methyl-benzoic acid (2) and 3-ferrocenylmethylidenimino-2-naphthoic acid (3). 1, 2 and 3 are stable in the solid state but easily hydrolyze in solution. This hydrolysis has been studied kinetically in a methanol-water medium. In order to increase the stability in solution to use these compounds as ligands, the imino group from 1, 2 and 3 was reduced by NaBH4 to give the amino derivatives 2-ferrocenylmethylamino-benzoic acid (4), 2-ferrocenylmethylamino-5-methyl-benzoic acid (5) and 3-ferrocenylmethylamino-2-naphthoic acid (6). 4, 5 and 6 are stable, both in the solid state and in solution, and potential chelating NO donor ligands containing ferrocenyl groups. The protonation of 4–6 and their complex formation with copper(II) have been investigated by potentiometry in dimethyl sulfoxide (dmso)-water (80:20 wt./wt.) mixtures at 25 °C and 0.1 mol dm−3 KClO4. The molecular structure of 5 has been determined by single-crystal X-ray methods. It crystallizes in the triclinic system, space group P 1 , with a = 6.1747(7), b = 9.539(1), c = 13.511(4) A , α = 88.99(1), β = 87.00(1), γ = 82.34(1)°, V = 787.6(3) A 3 and Z = 2 . An unusual feature of the ferrocene-containing ligand 5 in its interaction with nickel(II) ions was found. Cleavage of the CN bond of the secondary amine 5 and molecular rearrangement yields the protonated tertiary amine 2-bis(ferrocenylmethyl)ammonium-5-methyl-benzoic acid perchlorate (7). Compound 7 crystallizes in the monoclinic system, space group P21/c with a = 9.702(9), b = 27.153(17), c = 22.326(6) A , β = 97.39(6)°, V = 5833(12) A 3 and Z = 8 . Typical reversible oxidation waves were found for 4–7 whereas some degree of irreversibility was detected for their parent imines.

The fluorescent behaviour of the polyazacycloalkane containing naphthyl groups 1,4,8,11-tetrakis(naphthylmethyl)-1,4,8,11-tetraazacyclotetradecane (L 1 ) and its Cu 2+ complex in the presence of anions are compared in aqueous environment (THF:water 70:30 v/v, 0.1 mol dm −3 tetrabutylammonium perchlorate, 25°C). The emission fluorescent intensity of the L 1 –Cu 2+ system is selectively enhanced in the presence of sulfate at acid pH.