Person:
Moreno Jiménez, Florencio

First Name

Florencio

Last Name

Moreno Jiménez

URI

https://hdl.handle.net/20.500.14352/79918

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Óptica y Optometría

Department

Química Orgánica

Area

Química Orgánica

Identifiers

Full item page

Search Results

Now showing 1 - 10 of 37

Nuevas metodologías en la cociclación en síntesis de pirimidinas
(2002) Moreno Jiménez, Florencio; García Martínez, Antonio; Herrera Fernández, Antonio
En esta tesis doctoral se demuestra que el mecanismo de las cetonas enolizables con anhidrido trifluormetanosulfonico (tf2o) transcurre a través de la formación de un catión trifiiloxicarbenio como intermedio. A partir de este punto se abordan distintos aspectos mecanísticos de la reactividad de cetonas y aldehidos con tf2o en presencia de nitrilos. De forma paralela se desarrollan las aplicaciones sintéticas derivadas de esta reactividad, presentando nuevos métodos de síntesis de alquil y aril-pirimidinas, 2,4-diiodopirimidinas, isoureas, guanidinas y 2,4-bis(metiltio)-pirimidinas empleadas posteriormente para la obtención de 2,4-bis(metilsulfonil)pirimidinas, uracilos, 4-amino-2-metilsulfonil-pirimidinas y 2,4-diaminopirimidinas.
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.
Circularly Polarized Luminescence by Visible-Light Absorption in a Chiral O-BODIPY Dye: Unprecedented Design of CPL Organic Molecules from Achiral Chromophores
(Journal of the American Chemical Society, 2014) Márquez Sánchez-Carnerero, Esther María; Moreno Jiménez, Florencio; Lora Maroto, Beatriz; Rodríguez Agarrabeitia, Antonia; Ortíz García, María Josefa; Vo, Bryan G.; Muller, Gilles; Moya Cerero, Santiago de la
Circularly polarized luminescence (CPL) in simple (small, nonaggregated, nonpolymeric) O-BODIPYs(R)-1 and (S)-1 by irradiation with visible light is first detected as proof of the ability of a new structural design to achieve CPL from inherently achiral monochromophore systems in simple organic molecules. The measured level of CPL (|glum|) in solution falls into the usual range of that obtained from other simple organic molecules (10−5−10−2range), but the latter having more complex architectures since axially chiral chromophores or multichromophore systems are usually required. The new design is based on chirally perturbing the acting achiral chromophore by orthogonally tethering a single axially chiral 1,1′-binaphtyl moiety to it. The latter does not participate as a chromophore in the light-absorption/emission phenom-enon. This simple design opens up new perspectives for the future development of new small-sized CPL organic dyes (e.g., those based on other highly luminescent achiral chromophores and/or chirally perturbing moieties), as well as for the improvement of the CPL properties of the organic molecules spanning their use in photonic applications.
The Mechanism of Hydrolysis of Aryldiazonium Ions Revisited: Marcus Theory vs. Canonical Variational Transition State Theory
(European Journal of Organic Chemistry, 2013) García Martínez, Antonio; Moya Cerero, Santiago de la; Osío Barcina, José de Jesús; Moreno Jiménez, Florencio; Lora Maroto, Beatriz
Several models, theoretical levels and computational methods, all based on the canonical variational transition state approximation, have been used to predict both the experimental activation energies (ΔEexp≠) and the experimental activation free energies (ΔGexp≠) for the hydrolysis of aryldiazonium ions. It is demonstrated that the computation of activation energies (ΔE≠), instead of activation free energies (ΔG≠), agrees better with the corresponding experimental data, showing that the employed computational methods do not afford reliable entropic contributions to the free energy barriers in the case of the studied reaction. However, the most fitted computations of ΔE≠ were not able to clearly differentiate between the mechanisms proposed for this interesting reaction (SN1, SN2 and water cluster). In contrast, the use of the Marcus theory (hyperbolic-cosine equation) instead of the canonical variational transition state theory leads to excellent agreement between the in-water-computed activation energies (ΔEwM≠) and the corresponding ΔEexp≠ values for the SN2 mechanism, but far beyond the limit of error for the SN1 process. The validity of the Marcus theory for the studied SN1 and SN2 reactions is ensured by the fact that both reactions can be described as SET processes. On the other hand, apparently compelling evidence against the SN2 mechanism, such as 13C KIEs and experimental observation of N2 scrambling, are also discussed and alternative explanations are proposed.
Exploring N-BODIPYs as Privileged Scaffolds to Build Off/On Fluorescent Sensors by PET
(Proceedings, 2019) Ray Leiva, César; Schad, Christopher; Avellanal-Zaballa, Edurne; Moreno Jiménez, Florencio; Bañuelos, Jorge; Maroto, Beatriz Lora; Moya Cerero, Santiago de la
A new N-boron dipyrromethene (N-BODIPY) substituted with a crown ether moiety has been synthesized by reaction of an F-BODIPY with a crown-ether-substituted bis(sulfonamide). The workability of this N-BODIPY as an off/on sensor for cations by modulation of a photoinduced electron transfer (PET) is explored. The new N-BODIPY demonstrates the possibilities of functionalization of these still unexplored but promising dyes.
Manipulating Charge-TransferStates in BODIPYs: A ModelStrategy to Rapidly Develop Photodynamic Theragnostic Agents
(Chemistry: a european journal, 2020) Jiménez González, Josué; Prieto Montero, Ruth; Lora Maroto, Beatriz; Moreno Jiménez, Florencio; Ortíz García, María Josefa; Oliden Sánchez, Ainhoa; López Arbeloa, Íñigo María; Martínez Martínez, Virginia; Moya Cerero, Santiago de la
On the basis of a family of BINOL (1,1′-bi-2-naphthol)-based O-BODIPY (dioxyboron dipyrromethene) dyes, it is demonstrated that chemical manipulation of the chromophoric push–pull character, by playing with the electron-donating capability of the BINOL moiety (BINOL versus 3,3'-dibromoBINOL) and with the electron-acceptor ability of the BODIPY core (alkyl substitution degree), is a workable strategy to finely balance fluorescence (singlet-state emitting action) versus the capability to photogenerate cytotoxic reactive oxygen species (triplet-state photosensitizing action). It is also shown that the promotion of a suitable charge-transfer character in the involved chromophore upon excitation enhances the probability of an intersystem crossing phenomenon, which is required to populate the triple state enabling singlet oxygen production. The reported strategy opens up new perspectives for rapid development of smarter agents for photodynamic theragnosis, including heavy-atom-free agents, from a selected organic fluorophore precursor.
Unprecedented induced axial chirality in a molecular BODIPY dye: strongly bisignated electronic circular dichroism in the visible region
(Chemical Communications, 2013) Márquez Sánchez-Carnerero, Esther María; Moreno Jiménez, Florencio; Lora Maroto, Beatriz; Rodríguez Agarrabeitia, Antonia; Bañuelos Prieto, Jorge; Arbeloa, Teresa; López Arbeloa, Íñigo María; Ortíz García, María Josefa; Moya Cerero, Santiago de la
Enantiomeric bis(BODIPYs) 1a and 1b exhibit strong bisignated ECD due to the formation of a stable helical conformation with induced axial chirality, which allows efficient excito coupling of the BODIPY chromophores in the Vis region.
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.
Chiral Organic Dyes Endowed with Circularly Polarized Laser Emission
(Journal of Physical Chemistry C, 2017) Jiménez González, Josué; Cerdán Pedraza, Luis; Moreno Jiménez, Florencio; Maroto, Beatriz Lora; García Moreno, Inmaculada; Lunkley, Jamie L.; Muller, Gilles; Moya Cerero, Santiago de la
The direct generation of efficient, tunable, and switchable circularly polarized laser emission (CPLE) would have far-reaching implications in photonics and material sciences. In this paper, we describe the first chiral simple organic molecules (SOMs) capable of simultaneously sustaining significant chemical robustness, high fluorescence quantum yields, and circularly polarized luminescence (CPL) ellipticity levels (|glum|) comparable to those of similar CPL-SOMs. All these parameters altogether enable efficient laser emission and CPLE with ellipticity levels 2 orders of magnitude stronger than the intrinsic CPL ones.