Person:
García Fresnadillo, David

First Name

David

Last Name

García Fresnadillo

URI

https://hdl.handle.net/20.500.14352/76205

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Químicas

Department

Química Orgánica

Area

Química Orgánica

Identifiers

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Now showing 1 - 10 of 14

Project number: 166
Determinantes del bajo rendimiento académico universitario: análisis del impacto de las variables previas al acceso a la universidad
(2022) García Fresnadillo, David; Constante Amores, Israel Alexander; Cuervo Rodríguez, María Rocío; Martínez Sánchez, Juan Carlos; Moreno Jiménez, Florencio; Ramírez Castellanos, Julio
Mejora del rendimiento académico en la asignatura Química de 1º de Grado en Química, Ing. Química, Optometría y Biología. Enfoque preventivo y diagnóstico. Análisis de factores (sociodemográficos, académicos y uso de TIC) al inicio de 1º curso.
Project number: 365
Influencia del cambio en la metodología de enseñanza-aprendizaje y de evaluación, de presencial a on-line, en el aprendizaje de contenidos, competencias y en el rendimiento académico de estudiantes de primer curso de grado de la UCM
(2021) García Fresnadillo, David; Cuervo Rodríguez, María Rocío; Moreno Jiménez, Florencio; Ramírez Castellanos, Julio; Arrieta Dillon, Marina Patricia; Constante Amores, Israel Alexander; Martínez Sánchez, Juan Carlos
Debido a Covid-19, el cambio en el modo de enseñar y evaluar al alumnado, con más énfasis en el campus virtual, afectará sensiblemente al curso 2020-2021. Se analiza la influencia sobre el aprendizaje y rendimiento académico de la asignatura Química en los estudiantes de 1º curso de varios grados de ciencias de la UCM.
An Ultra‐Long‐Lived Triplet Excited State in Water at Room Temperature: Insights on the Molecular Design of Tridecafullerenes
(Angewandte Chemie International Edition, 2021) Ramos Soriano, Javier; Pérez Sánchez, Alfonso; Ramírez Barroso, Sergio; Illescas, Beatriz M.; Azmani, Khalid; Rodríguez Fortea, Antonio; Poblet, Josep M.; Hally, Cormac; Nonell, Santi; García Fresnadillo, David; Rojo, Javier; Martín León, Nazario
Suitably engineered molecular systems exhibiting triplet excited states with very long lifetimes are important for high-end applications in nonlinear optics, photocatalysis, or biomedicine. We report the finding of an ultra-long-lived triplet state with a mean lifetime of 93 ms in an aqueous phase at room temperature, measured for a globular tridecafullerene with a highly compact glycodendrimeric structure. A series of three tridecafullerenes bearing different glycodendrons and spacers to the C60 units have been synthesized and characterized. UV/Vis spectra and DLS experiments confirm their aggregation in water. Steady-state and time-resolved fluorescence experiments suggest a different degree of inner solvation of the multifullerenes depending on their molecular design. Efficient quenching of the triplet states by O2 but not by waterborne azide anions has been observed. Molecular modelling reveals dissimilar access of the aqueous phase to the internal structure of the tridecafullerenes, differently shielded by the glycodendrimeric shell.
Photochemical Oxidation of Thioketones by Singlet Molecular Oxygen Revisited: Insights into Photoproducts, Kinetics, and Reaction Mechanism
(Journal of organic chemistry, 2015) Sánchez Arroyo, Antonio José; Pardo Botero, Zulay D.; Moreno Jiménez, Florencio; Herrera Fernández, Antonio; Martín, Nazario; García Fresnadillo, David
Photosensitized oxidation of trimethyl[2.2.1]-bicycloheptane thioketones by 1 O2 can yield more photoproducts than exclusively ketones and sulfines. Moreover, the ketone/sulfine ratio can be reversed when protic conditions and high thioketone concentrations are used, conversely to earlier results reporting ketones as the main photoproducts. A new mechanistic proposal for sulfine formation is suggested following intermolecular oxygen transfer from a peroxythiocarbonyl intermediate to a second thioketone molecule. Reaction quantum yields (10−5−10−2) depend on the reaction conditions and time. Sulfine production reaches a maximum at short irradiation times, whereas decomposition to the corresponding ketone is observed at long reaction times. When the thioketone substrate has a hydrogen atom at the α position a peroxyvinylsulfenic acid intermediate can be formed by proton transfer. Reaction of this intermediate with another thioketone molecule can yield more sulfine and its tautomeric vinylsulfenic acid, which dimerizes in situ to the thiosulfinate. The hydroperoxyl group of the peroxyvinylsulfenic acid can also rearrange to the α position, and by reaction with the starting thioketone, α-hydroxy thioketone and additional sulfine can be formed, while dehydration yields the α-oxo thioketone. In situ [2 + 2] and [4 + 2] self-cycloaddition of the α-oxo thioketone yields significant amounts of the corresponding adducts at prolonged irradiation times.
Project number: 290
Evaluación del impacto del perfil del alumnado en la valoración de la actividad docente del profesorado
(2019) Cuervo Rodríguez, M. Rocío; García Fresnadillo, David; Moreno Jiménez, Florencio; Ramírez Castellanos, Julio; García Pereira, Francisco Javier; Martínez Sánchez, Juan Carlos
En este proyecto se analiza el perfil de los estudiantes de primer curso en tres Grados (Química, Biología y Óptica-Optometría) de las Facultades de Ciencias de la UCM, detectando las carencias que presentan los estudiantes en una materia básica como la Química. Se comparan los resultados con los obtenidos en el curso académico 2016-2017. Asimismo se analiza la relación del perfil del alumnado con la valoración de la actividad docente del profesorado que realizan los estudiantes dentro del programa DOCENTIA.
Project number: 51
Introducción al diseño de Cursos Cero para materias básicas del primer curso de Grado en Ciencias mediante enseñanza virtual
(2017) Cuervo Rodríguez, María Rocío; García Fresnadillo, David; Moreno Jiménez, Florencio; Sánchez Arroyo, Antonio José; García Pereira, Francisco Javier; Martínez Sánchez, Juan Carlos
Evaluar, analizar la situación de partida de los alumnos de nuevo acceso al 1º curso de Grado en Facultades de Ciencias de la UCM (Biología, Óptica y Optometría y Química), y generar las bases para diseñar un Curso 0 de una materia básica, Química.
Rhodanine-based dyes absorbing in the entire visible spectrum
(Organic chemistry frontiers, 2017) Sandoval Torrientes, Rafael; Calbo, Joaquín; García Fresnadillo, David; Santos, José; Ortí, Enrique; Martín, Nazario
A series of new broad-absorbing dyes based on rhodanine derivatives conjugated with triarylamines using Q5 a fluorene backbone was synthesized. Spectroscopic and electrochemical characterizations, along with theoretical calculations at the B3LYP/cc-pVDZ level, revealed interesting properties of the dyes, which make the dyes efficiently absorb in the entire visible spectrum.
Exploring BODIPY Derivatives as Singlet Oxygen Photosensitizers for PDT
(Photochemistry and Photobiology, 2020) Prieto Moreno, Ruth; Prieto Castañeda, Alejandro; Sola Llano, Rebeca; Rodríguez Agarrabeitia, Antonia; García Fresnadillo, David; López Arbeloa, Íñigo María; Villanueva Oroquieta, Ángeles; Ortíz García, María Josefa; Moya Cerero, Santiago de la; Martínez Martínez, Virginia
This minireview is devoted to honoring the memory of Dr. Thomas Dougherty, a pioneer of modern photodynamic therapy (PDT). It compiles the most important inputs made by our research group since 2012 in the development of new photosensitizers based on BODIPY chromophore which, thanks to the rich BODIPY chemistry, allows a finely tuned design of the photophysical properties of this family of dyes to serve as efficient photosensitizers for the generation of singlet oxygen. These two factors, photophysical tuning and workable chemistry, have turned BODIPY chromophore as one of the most promising dyes for the development of improved photosensitizers for PDT. In this line, this minireview is mainly related to the establishment of chemical methods and structural designs for enabling efficient singlet oxygen generation in BODIPYs. The approaches include the incorporation of heavy atoms, such as halogens (iodine or bromine) in different number and positions on the BODIPY scaffold, and also transition metal atoms, by their complexation with Ir(III) center, for instance. On the other hand, low‐toxicity approaches, without involving heavy metals, have been developed by preparing several orthogonal BODIPY dimers with different substitution patterns. The advantages and drawbacks of all these diverse molecular designs based on BODIPY structural framework are described.
Singlet oxygen photosensitizing materials for point‐of‐use water disinfection with solar reactors
(ChemPhotoChem, 2018) García Fresnadillo, David
Singlet molecular oxygen (1O2) is a potent electrophile and a strong oxidizing agent and can be easily generated by photosensitization via illumination of appropriate dyes with visible light. This short-lived reactive oxygen species is able to photooxidize many electron-rich organic compounds and, therefore, 1O2 can damage many cellular components, such as membrane lipids, proteins and DNA, causing the photoinactivation of microorganisms in water. This Review summarises the most relevant work to date on solar water disinfection by photocatalytic 1O2 production, using photosensitizing materials suitable for their use in solar reactors for water treatment. The prototypes were equipped with compound parabolic collectors of sunlight and designed for point-of-use water treatment. The choice of the type of dye (RuII complexes or fullerenes) and polymeric support for the preparation of the 1O2 photosensitizing material, as well as the most important photophysical and operational parameters to be optimized to achieve efficient water disinfection with solar reactors, will be discussed.
Project number: 201
Aprendizaje mentorizado en grupo y evaluación formativa metacognitiva centrados en el perfil preuniversitario del alumnado de primer curso de grado
(2019) Cuervo Rodríguez, María Rocío; García Fresnadillo, David; Moreno Jiménez, Florencio; Ramírez Castellanos, Julio; García Pereira, Francisco Javier; Martínez Sánchez, Juan Carlos; Jiménez González, Josué; Arrieta Dillon, Marina Patricia