Search results for "Química analítica"
showing 10 items of 98 documents
Regio- and stereo-selectivity in the intramolecular quenching of the excited benzoylthiophene chromophore by tryptophan
2000
Laser flash photolysis studies on the photobehaviour of a series of bichromophoric derivatives bearing benzoylthiophene and tryptophan groups have shown that the efficiency of the intramolecular quenching process depends on both the stereochemistry of the chiral centers and the relative ketone versus tryptophan orientation. Perez Prieto, Julia, Julia.Perez@uv.es
Photoluminescence study of terbium-exchanged ultrastable Y zeolites: Number of species, photoluminescence decays and decay-associated spectra
2008
Terbium-exchanged ultrastable Y (USY) zeolites were investigated by using time-resolved photoluminescence spectroscopy techniques and methods. To determine the distribution of terbium species in USY zeolites together with their photoluminescence properties, several analysis methods for the time-resolved luminescence spectra were used such as the area normalization of time-resolved photoluminescence spectra, singular value decomposition, global nonlinear least squares, and the maximum entropy. Except for a questionable long lifetime, small contribution of a terbium species with lifetime of 1.9¿2.1 ms, all the experimental and analysis results converged to a two terbium species distribution w…
Highly phosphorescent perfect green emitting iridium(iii) complex for application in OLEDs.
2007
A novel iridium complex, [bis-(2-phenylpyridine)(2-carboxy-4-dimethylaminopyridine)iridium(III)] (N984), was synthesized and characterized using spectroscopic and electrochemical methods; a solution processable OLED device incorporating the N984 complex displays electroluminescence spectra with a narrow bandwidth of 70 nm at half of its intensity, with colour coordinates of x = 0.322; y = 0.529 that are very close to those suggested by the PAL standard for a green emitter. Bolink, Henk, Henk.Bolink@uv.es ; Coronado Miralles, Eugenio, Eugenio.Coronado@uv.es ; Garcia Santamaria, Sonsoles Amor, Sonsoles.Garcia@uv.es
Solution processable phosphorescent dendrimers based on cyclic phosphazenes for use in organic light emitting diodes (OLEDs)
2008
A novel solution processable phosphorescent dendrimer based on cyclic phosphazene (CP) cores has been prepared and used as emissive layers in simple OLED architectures, providing efficiencies of 24.0 cd A^-1 and 16.7 lm W^-1. Bolink, Henk, Henk.Bolink@uv.es ; Garcia Santamaria, Sonsoles Amor, Sonsoles.Garcia@uv.es
Risk assessment of mycotoxins in cereals = Evaluación del riesgo de micotoxinas en cereales
2015
Las micotoxinas son un grupo de sustancias producidas por diferentes especies de hongos filamentosos. La presencia de micotoxinas en los alimentos constituye un problema de salud pública a nivel mundial. En la Unión Europea se han establecido contenidos máximos en materias primas y alimentos para 14 micotoxinas, consideradas de mayor relevancia para la salud del consumidor. En la actualidad se está prestando atención a otros grupos de micotoxinas menos estudiadas, como las micotoxinas emergentes de Fusarium, entre las que se encuentran la beauvericina, las eniatinas y la fusaproliferina. Se trata de micotoxinas de creciente interés en el campo de la seguridad alimentaria por presentar una e…
A chirality-induced alpha phase and a novel molecular magnetic metal in the BEDT-TTF/tris(croconate)ferrate(iii) hybrid molecular system
2006
The novel paramagnetic and chiral anion [Fe(C5O5)3]32 has been combined with the organic donor BEDT-TTF (= ET = bis(ethylenedithio)tetrathiafulvalene) to yield the first chirality- induced α phase and a paramagnetic metal. Gomez Garcia, Carlos, Carlos.Gomez@uv.es ; Coronado Miralles, Eugenio, Eugenio.Coronado@uv.es ; Gimenez Saiz, Carlos, Carlos.Gimenez@uv.es
Guía multimedia de operaciones básicas en análisis químico, farmacéutico y medioambiental
2008
En el presente proyecto se ha desarrollado una guía multimedia en formato electrónico como recurso de apoyo para la enseñanza y aprendizaje de las técnicas básicas del laboratorio analítico. La guía contiene ocho apartados donde los estudiantes pueden encontrar fácilmente información sobre las características de los reactivos químicos, descripción del material de laboratorio de uso frecuente, cómo se debe manejar y limpiar dicho material, instrucciones para no cometer errores en la operación de pesada de un sólido, como preparar de forma correcta una disolución, como llevar a cabo una valoración y las distintas etapas necesarias para calibrar un instrumento de medida, desde la preparación d…
Efficient deep-red light-emitting electrochemical cells based on a perylenediimide-iridium-complex dyad
2009
A two-layer light-emitting electrochemical cell device based on a new perylenediimide-iridium-complex dyad is presented emitting in the deep-red region with high external quantum efficiencies (3.27%). Costa Riquelme, Ruben Dario, Ruben.Costa@uv.es ; Orti Guillen, Enrique, Enrique.Orti@uv.es ; Bolink, Henk, Henk.Bolink@uv.es ; Gierschner, Johannes, Johannes.Gierschner@uv.es
Comparative enantioseparation of planar chiral ferrocenes on polysaccharide‐based chiral stationary phases
2022
Planar chiral ferrocenes are well-known compounds that have attracted interest for application in synthesis, catalysis, material science, and medicinal chemistry for several decades. In spite of the fact that asymmetric synthesis procedures for obtaining enantiomerically enriched ferrocenes are available, sometimes, the accessible enantiomeric excess of the chiral products is unsatisfactory. In such cases and for resolution of racemic planar chiral ferrocenes, enantioselective high-performance liquid chromatography (HPLC) on polysaccharide-based chiral stationary phases (CSPs) has been used in quite a few literature articles. However, although moderate/high enantioselectivities have been ob…
Unexpected photochemistry and charge-transfer complexes of [CB11H12]2 carborane
2008
Although the [CB11H12]¯carborane does not exhibit an absorption band inUV, its triplet excited state can be generated upon 308 nm laser excitation; also unexpectedly carborane acts as electron donor forming a charge transfer complex with methylviologen that upon illumination gives rise to viologen radical cation. Galletero Pedroche, M.Sales, Sales.Galletero@uv.es