Improved Suzuki–Miyaura reaction conversion efficiency using magnetic nanoparticles and inductive heating

The use of magnetic nanoparticles in C–C coupling reactions enables the facile recovery of the catalyst under environmentally friendly conditions. Herein, the synthesis of Pd/Fe@Fe3O4 nanoparticles by the reduction of Pd2+ and oxidation of Fe on the surface of preformed Fe@Fe3O4 is reported. The nanoparticles were characterized using a variety of analytical techniques (transmission electron microscopy, Mössbauer spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction) to determine their size, structure, and chemical composition. The catalytic efficiency of these nanoparticles in classical Suzuki–Miyaura coupling reactions was investigated. The nanoparticles achieved high catalytic activity with the application of local heating by an alternating magnetic field. An investigation was conducted at identical temperatures to compare global heating with the application of an external magnetic field; magnetic heating demonstrated excellent substrate conversion in lesser time and at a lower temperature. The catalyst could also be recycled and reused three times, with ~ 30% decrease in the substrate conversion, which is most likely due to the agglomeration of the Pd nanoparticles or poisoning of the Pd catalyst. This approach, which takes advantage of the catalytic activity and magnetic susceptibility of magnetic nanoparticles, can be applied to several organic transformations to improve their efficiencyWe are grateful for financial support provided by the Government of Spain through project PGC2018-095642-B-I00. In addition, A. Villacampa and L. Duque acknowledge the Community of Madrid for Predoctoral contracts PEJD-2019-PRE/IND-15356 and PEJ-2019-AI/IND-12506, respectively, co-financed by the European Social Fund through the Youth Employment Operational Program and the Youth Employment Initiative (YEI

Metabolic syndrome improvement in depression six months after prescribing simple hygienic-dietary recommendations

BACKGROUND: Changes in diet and exercise have been separately demonstrated to improve Depression, although scientific evidence available is scarce. In a previously published controlled study, just recommending these and other lifestyle measures (sleep restriction and sunlight exposure) in combination once, patients experienced improvements in their depressive symptoms six months later. In this sample, one in three depressive patients had metabolic syndrome (MetS) at baseline. First line treatment of MetS condition is hygienic-dietetic, being Mediterranean diet and exercise especially important. Therefore we analyzed if lifestyle recommendations also improved their metabolic profile. FINDINGS: During the sixth month evaluation, a smaller number of patients from the group receiving hygienic-dietary recommendations met MetS criteria comparing with the control group. CONCLUSIONS: This study suggests that costless lifestyle recommendations, such as exercise and Mediterranean diet, have the capacity to promote both mental and physical health in a significant proportion of depressive patients. Further research is needed to confirm or discard these preliminary findings

Síntesis de complejos de coordinación y organometálicos ciclometalados de paladio(II) con ligandos derivados de pirazol

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química. Fecha de lectura: 6 de Julio de 199

Dielectric analysis of photocrosslinked and post-sulfonated styrene-ethylene-butylene-styrene block copolymer based membranes

A series of UV photocrosslinked and post-sulfonated membranes based on blends of styrene-ethylene-butylene-styrene triblock copolymer (SEBS) and divinylbenzene (DVB) were considered for the preparation of electrolytes for proton exchange membrane fuel cell (PEMFC) applications. Macromolecular dynamics of SEBS and SEBS-DVB membranes below and above the T, were analysed using dielectric thermal analysis (DETA). A sub-Tg intramolecular non-cooperative dielectric relaxation and two main relaxations, corresponding to the glass transitions of ethylene-butylene (EB) and styrene (S) blocks, were identified in the dielectric relaxation spectrum. The photocrosslinking and post-sulfonation processes affect to the entire dielectric relaxation spectrum, the apparent activation energy and the fragilities of both styrene (S) and ethylene-butylene (EB) blocks. Understanding the restrictions on the segmental mobility at low and high scale caused by both photocrosslinking and subsequent sulfonation is basic to provide an approach to ionic diffusivities. A correlation between relaxations processes and the performance of these membranes in H/O – PEM single cells allows to estimate the behaviour of these membranes and to reengineer them, depending on the modification of the desired cell performance.The authors would like to thank the support of the European Union is through the European Regional Development Funds (ERDF) and the Spanish Ministry of Economy, Industry and Competitiveness, for the research projects POLYDECARBOCELL (ENE2017-86711-C3-1-R), REPICOMES (ENE2017-90932-REDT) and UPV- (PAID -10-19) SUB-1 grant for R. Teruel

Layered gamma-zirconium phosphate as novel semiconductor for dye sensitized solar cells: Improvement of photovoltaic efficiency by intercalation of a ruthenium complex-viologen dyad

[EN] The performance of photovoltaic cells using as semiconductor a film of layered γ-zirconium phosphate (γ-ZrP) containing Ru(bpy) 3 and bipyridinium ions (viologens) as electron relays has been studied. The materials are easily prepared by intercalation of Ru complexes and the bipyridinium ions into preformed γ-ZrP nano sheets as colloidal solutions in the appropriate solvent and concentration. High loading of these two guests has been obtained as determined by elemental analysis. Inclusion of Ru(bpy) 3 complex and bipyridinium in the intergallery spaces of γ-ZrP can be assessed by powder XRD monitoring of the d 100 peak. A dyad was also synthesized where the Ru(bpy) 3 and the 4,4′-bipyridinium were covalently connected by a four-methylene tether. The semiconducting behavior of layered γ-ZrP was supported by cyclic voltammetry (reversible reduction peak at -0.6 V), observation of photocurrent and Mott-Schottky measurements (flat band potential ∼-1.3 V vs. NHE) of thin films of this material supported on FTO electrode. Photovoltaic cells based on γ-ZrP containing Ru(bpy) 3, exhibited similar V OC (∼0.5 V) and fill-factor values (0.3-0.4), differing in the current density and therefore in their efficiency. The maximum efficiency was obtained for the material containing high loading of the dyad (J SC = 0.383 mA/cm 2, efficiency 0.1%). The photo response spectrum shows that the main limitation of these materials is still the inefficient photo sensitization of the semiconductor by the dye, probably due to the high negative flat band potential of γ-ZrP. © 2011 The Royal Society of Chemistry.The UPV-CSIC group is grateful to the Spanish MICINN for grant CTQ2009-11863. The UAM group thanks ERCROS-Farmacia S.A. for indirect funding and regrets that the financial backing from MICINN has been negated after the generous grants received in the near past (MAT2002-03243, MAT2006-00570).Atienzar Corvillo, PE.; De Victoria-Rodriguez, M.; Juanes, O.; Rodríguez-Ubis, J.; Brunet, E.; García Gómez, H. (2011). Layered gamma-zirconium phosphate as novel semiconductor for dye sensitized solar cells: Improvement of photovoltaic efficiency by intercalation of a ruthenium complex-viologen dyad. Energy and Environmental Science. 4(11):4718-4726. https://doi.org/10.1039/C1EE02158CS4718472641

Layered Zirconium phosphate intercalated with Ru(bpy)3-viologen dyads as unusual materials for dye-sensitized solar cells: Improving efficiency by double sensitization

The intercalation materials prepared from the laminar salt gamma-zirconium phosphate and various dyads formed from Ru(bpy)(3) and viologens were tested as photoactive components in dye-sensitised solar cells. The efficiencies significantly increased, up to 0.2 %, when the materials were treated with the panchromatic N535 dye. A mechanism for this double sensitisation process is proposed, which should enable further improvement of these gamma-ZrP-based materials as a reasonable alternative to the usual Ti-based dye-sensitised solar cells.The group from Universidad Autonoma de Madrid (UAM) is grateful to ERCROS-Farmacia SA (Aranjuez, Spain) for sponsoring the UAM-ERCROS Chair in Chemistry that generously funded this work, in part. The group from Universidad del Pais Valenciano-Consejo Superior de Investigaciones Cientificas (UPV-CSIC) group is grateful to the Spanish former Ministerio de Ciencia e Innovacion de Espana (MICINN) for grant CTQ2012-32315. P.A. thanks the MICINN for a Juan de la Cierva research contract.De Victoria-Rodriguez, M.; Atienzar Corvillo, PE.; Juanes, O.; Rodriguez Ubis, JC.; Brunet, E.; García Gómez, H. (2014). Layered Zirconium phosphate intercalated with Ru(bpy)3-viologen dyads as unusual materials for dye-sensitized solar cells: Improving efficiency by double sensitization. Australian Journal of Chemistry. 67(3):389-397. https://doi.org/10.1071/CH13451S38939767

Grupo de Anatomía Virtual y de Simulación AVS

Podeu consultar la Setena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/4335