598 research outputs found
Synthesis and reactivity of half-sandwich (η 5 -C 5 Me 5 )Ir(iii) complexes of a cyclometallated aryl phosphine ligand
Reaction of the Ir(iii) dimer [(η 5 -C 5 Me 5 )IrCl 2 ] 2 with PMeXyl 2 (Xyl = 2,6-C 6 H 3 Me 2 ), in the presence of the poorly coordinating base 2,2,6,6-tetramethyl piperidine, gives a chloride complex 1-Cl, resulting from hydrogen chloride elimination involving one of the phosphine benzylic hydrogen atoms and concomitant cyclometallation. Related compounds containing other halide or pseudohalide ligands, 1-Br, 1-Cl, 1-SCN, can be made, the latter featuring S-coordination of the ambidentate thiocyanate to the soft Ir(iii) Lewis acid centre, as suggested by IR data and demonstrated by X-ray crystallography. Hydride 2-H, and alkyl derivatives 3 (Me) and 4 (CH 2 SiMe 3 ) can also be prepared from 1-Cl and appropriate hydride and alkylating reagents. An interesting H/D exchange chemistry that occurs in the presence of CD 3 OD has been disclosed for 1-Cl, 1-Br and 2-H. For the halide derivatives, deuterium incorporation takes place into the methylene and methyl sites of their cyclometallated ligand, whereas for 2-H only the hydride and methylene (Ir-CH 2 ) protons participate in the exchange, which is strikingly accelerated by catalytic amounts of acids.Ministerio de Ciencia e Innovación CTQ2010-17476Consolider-Ingenio2010 CSD2007-0000Junta de Andalucia FQM-119, P09-FQM-483
Validación al español de la escala de comparación de apariencia física hacia arriba y hacia abajo (Upacs-Dacs)
El origen de los colegios jesuítas de la provincia quitense y su incidencia en la educación
Jornadas sobre la Presencia Universitaria Española en América (6. 1992. Alcalá de Henares)La Provincia jesuita quitense incluyó Colegios tales como el Colegio Máximo\ud
de Quito, el Colegio Seminarío de San Luis de Quito; los Colegios de Guayaquil, Cuenca,\ud
Ibarra y Latacunga; asi como los Colegios de Pasto y Popayán, pertenecientes a la actual\ud
Colombia.\ud
Para el estudio de dichos Colegios hemos contado con el apoyo de diversas\ud
fuentes, todas del AHPTSJ, entre las que destacan: los documentos referidos a fundaciones y donaciones, los pleitos con otras órdenes, los testimonios de misioneros y su labor evangelizadora; pasando por las listas de sujetos y profesiones dentro de cada Colegio
Character and protagonist... and the Earth did not part
El propósito es establecer la existencia de un personaje principal (muchacho que aparece en las dos historias que sirven de marco a la obra) y de un protagonista (pueblo Chicano) en... and the earth did not part (Rivera, 1977). La justificación está en la dependencia del personaje principal con respecto al protagonista. Dado que el
primero está en una etapa de formación, sin el protagonista no podría completar su
propia identidad. El protagonista podría existir por sí mismo. Sin embargo, la presencia del muchacho coopera a dar unidad al conjunto de historias y anécdotas que tienen que ver con el pueblo Chicano, es decir con el protagonista
Character and protagonist... and the Earth did not part
El propósito es establecer la existencia de un personaje principal (muchacho que aparece en las dos historias que sirven de marco a la obra) y de un protagonista (pueblo Chicano) en... and the earth did not part (Rivera, 1977). La justificación está en la dependencia del personaje principal con respecto al protagonista. Dado que el
primero está en una etapa de formación, sin el protagonista no podría completar su
propia identidad. El protagonista podría existir por sí mismo. Sin embargo, la presencia del muchacho coopera a dar unidad al conjunto de historias y anécdotas que tienen que ver con el pueblo Chicano, es decir con el protagonista
Reactivity of a trans-[H-Mo≣Mo-H] Unit Towards Alkenes and Alkynes. Bimetallic Migratory Insertion, H-Elimination and Other Reactions
Complex [Mo2(H)2{μ-HC(NDipp)2}2(THF)2], (1·THF), reacts with C2H4 and PhCH[double bond, length as m-dash]CH2 to afford hydrido-hydrocarbyl and bis(hydrocarbyl) derivatives of the Mo[quadruple bond, length as m-dash]Mo bond. Reversible migratory insertion and β-hydrogen elimination, as well as reductive elimination and other reactions, have been uncovered. PhC[triple bond, length as m-dash]CH behaves instead as a Brönsted–Lowry acid towards the strongly basic Mo–H bonds of 1·THF.Ministerio de Economía y Competitividad CTQ2016-75193-PEuropean Research Council 75657
Generic skills of Cei-A3 Universities (Agrifood Campus of International Excellence)
Resumen basado en el de la publicaciónTítulo, resumen y palabras clave también en inglésSe pretende realizar un análisis de las competencias transversales de las distintas universidades que componen el consorcio del Campus de Excelencia Internacional en Agroalimentación (CeiA3). Como resultado se observa que existen un número escaso de competencias comunes, siendo de vital importancia la incorporación de las competencias transversales comunes a los estudios universitarios de las universidades del CeiA3 ya que constituyen un elemento integrador y vertebrador del campus de excelencia internacional agroalimentario.ES
Peanut Shell for Energy: Properties and Its Potential to Respect the Environment
The peanut (Arachys hypogaea) is a plant of the Fabaceae family (legumes), as are chickpeas, lentils, beans, and peas. It is originally from South America and is used mainly for culinary purposes, in confectionery products, or as a nut as well as for the production of biscuits, breads, sweets, cereals, and salads. Also, due to its high percentage of fat, peanuts are used for industrialized products such as oils, flours, inks, creams, lipsticks, etc. According to the Food and Agriculture Organization (FAO) statistical yearbook in 2016, the production of peanuts was 43,982,066 t, produced in 27,660,802 hectares. Peanuts are grown mainly in Asia, with a global production rate of 65.3%, followed by Africa with 26.2%, the Americas with 8.4%, and Oceania with 0.1%. The peanut industry is one of the main generators of agroindustrial waste (shells). This residual biomass (25–30% of the total weight) has a high energy content that is worth exploring. The main objectives of this study are, firstly, to evaluate the energy parameters of peanut shells as a possible solid biofuel applied as an energy source in residential and industrial heating installations. Secondly, different models are analysed to estimate the higher heating value (HHV) for biomass proposed by different scientists and to determine which most accurately fits the determination of this value for peanut shells. Thirdly, we evaluate the reduction in global CO2 emissions that would result from the use of peanut shells as biofuel. The obtained HHV of peanut shells (18.547 MJ/kg) is higher than other biomass sources evaluated, such as olive stones (17.884 MJ/kg) or almond shells (18.200 MJ/kg), and similar to other sources of biomass used at present for home and industrial heating applications. Different prediction models of the HHV value proposed by scientists for different types of biomass have been analysed and the one that best fits the calculation for the peanut shell has been determined. The CO2 reduction that would result from the use of peanut shells as an energy source has been evaluated in all production countries, obtaining values above 0.5 ‰ of their total emissions
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