Examinando por Autor "Gala, Elena"

Mostrando 1 - 6 de 6

Comparing the microstructure and photovoltaic performance of 3 perylene imide acceptors with similar energy levels but different packing tendencies
(Royal Society of Chemistry, 2022) Adel, Rana; Gala, Elena; Alonso-Navarro, Matías J.; Gutierrez-Fernandez, Edgar; Martín, Jaime; Stella, Marco; Martinez-Ferrero, Eugenia; de la Peña, Alejandro; Harbuzaru, Alejandra; Ramos, M. Mar; Ponce Ortíz, Rocío; Segura, José L.; Campoy-Quiles, Mariano
While it is widely recognized that microstructure plays an important role in the performance of organic photovoltaics (OPV), systematic studies are often challenging, as varying the molecular packing through typical chemical means (such as sidechain tuning) often affects the molecular energy levels, thus preventing a clear correlation. In this work we present the synthesis of three perylene imide (PI) based electron acceptors with almost identical energy levels, but distinct packing tendencies. We confirm our initial hypothesis by measuring solution and solid-state absorption, and cyclic voltammetry as well as characterizing the films by grazing incidence wide angle X-ray scattering (GIWAXS). In a second step, we repeat the characterization of the three materials in blends with two polymer donors, namely PCDTBT or PBDBT, whose energy levels are well aligned with those of the PI acceptors, and which, additionally, exhibit different degrees of structural order. We show how the initial strong difference between acceptors is partially blurred in blends, but still critical. Finally, we correlate our structural data with OPV devices made with the corresponding six blends. Our data suggest that a good donor acceptor marriage should ensure good energy alignment but also exhibit complementary crystallization tendencies of the two components.
Post-synthetic modification of covalent organic frameworks with active manganese centers for electrocatalytic CO2 reduction in water
(The Royal Society of Chemistry, 2024-11-26) Gala, Elena; Dubed Bandomo, Geyla C.; Mattia, Vettori; Sergio, Royuela; Marcos, Martínez-Fernández; José I., Martínez; Elena, Salagre; Enrique G., Michel; Félix, Zamora; Julio , Lloret-Fillol; José L., Segura
The development of effective catalysts for the CO2 reduction reaction (CO2RR) is essential for transforming atmospheric CO2 into valuable chemical scaffolds. While numerous catalysts have been developed for the CO2RR, few are suitable for use in aqueous systems due to inherent design challenges. In this context, Covalent Organic Frameworks (COFs) have emerged as promising materials for the CO2RR in water, offering potential solutions to these challenges. Thanks to their porosity, high surface area and crystalline structure, COFs are excellent hosts for single-atom catalysts (SACs), enabling the immobilization of high-value species and their utilization in heterogeneous catalytic processes. For this reason, we have explored the catalytic activity of a terpyridine–manganese complex integrated into a COF lattice, which was successfully synthesized and characterized, confirming the presence of the metal ion in the material with spectroscopic techniques such as XPS and EDS. This new material has proved to be an active heterogeneous catalyst for the CO2RR in water as solvent, achieving a faradaic yield of 42% for CO at 300 mV overpotential and 16% for formate when 600 mV was applied. Furthermore, an ab initio theoretical study was performed to provide a plausible mechanism of the CO2RR to elucidate the CO evolution pathway.
Real-time spectroscopic analysis enabling quantitative and safe consumption of fluoroform during nucleophilic trifluoromethylation in flow.
(American Chemical Society, 2017-12-07) Musio, Biagia; Gala, Elena; Ley, Steven V.
The productive use of toxic waste materials derived from industrial processes is one of the main goals of modern chemical research to increase sustainability of the large-scale production. Here we devise a simple and robust strategy for the utilization of trifluoromethane, obtained in large quantities from polytetrafluoroethylene manufacture, and the conversion of this greenhouse gas into valuable fluorinated compounds. The generation of the trifluoromethyl carbanion and its direct and complete consumption through trapping with a number of electrophiles were achieved by a fully contained flow reactor setup. The adoption of modern in-line analytical tools, such as portable Fourier transform infrared and nuclear magnetic resonance devices, allowed the accurate reagent dosing with considerable benefits in terms of controlling the environmental impact during this continuous process. The advantages of the method, with respect to the batch procedure, will be discussed and demonstrated experimentally.
Regioselective Synthesis of 2-Amino-5-(or 3-)arylazo- Substituted Pyridines and Pyrazines from Pyridinium N-Aminides
(Wiley-VCH Verlag GmbH & Co. KGaA, 2016-04-19) Gala, Elena; Reyes, M. José; Alvarez-Builla, Julio; Izquierdo, M. Luisa
Studies on the preparation of aminobipyridines and bipyridine sultams via an intramolecular free radical pathway
(ROYAL SOC CHEMISTRY, 2020-03-04) Recio, Javier; Filace, Fabiana; Gala, Elena; Pérez-Redondo, Adrián; Álvarez-Builla, Julio; Burgos, Carolina
A variety of aminated bipyridines and bipyridine sultams are prepared by intramolecular radical [1,5]-ipso and [1,6]-ortho substitutions, using a sulfonamide as a linker to connect the pyridyl radical to the pyridine under attack. For the cases studied, different regiochemistries are observed depending on the initial position of the sulfonamide linker.
Synthesis of Florbetapir aza-analogues using chemistry of pyridinium N-aminides
(ARKAT USA, 2021-12-17) Gala, Elena; Recio, Javier; Álvarez-Builla, Julio; Izquierdo, M.Luisa
Neuroimaging of β-amyloid (Aβ) plaques in brain, employing Positron Emission Tomography (PET) has enabled early diagnosis of Alzheimer’s Disease and, although different 18F radiolabeled markers as Florbetapir and Florbetaben are already in the market, new molecules with better affinity and selectivity to Aβ plaques should be explored. In this article, two aza-analogues of Florbetapir have been synthesized from Pyridinium N-aminides. The new aza-analogues were prepared following straightforward synthetic routes under mild conditions. Although the products have been obtained using stable 19F, the methods are compatible with the future use of 18F, to generate products to be tested in the development of new PET reagents.