, SANHUEZA FRIGOLETT, JUAN MANUEL, Dreyse, Paulina A., Santander-Nelli, Mireya, Zambrano, David, Rosales, Luis, Sanhueza, Luís Manuel

The structures and electronic properties of a series of cyclometalated Ir(III) complexes with substituted dppz ancillary ligand (dppz: dipyrido[3,2-a:2?,3?-c]phenazine) including tert-butyl, pyrrolidine ring, and alkoxys substituents as donor group have been theoretically study. With the aim of highlight the attractive qualities of each system for their use as luminescent material, the effects of the electron-donor substituents onto dppz was evaluated on the structural, charge transport, absorption, and phosphorescent properties. The effect of the substituent was studied on the modulation of the bright and dark triplet states. Main results show that ortho-methoxy and tert-butyl substituents act as lower electron-donating groups, then, efficient electron donation ability was displayed with alkoxy (ethoxy and propoxy) substituents. The best performance was found in a complex with pyrrolidine ring according since their phosphorescence is favored, highlighting their larger electric transition dipole moment value, proposing this system as potential candidate to LEC technology. © 2020 Elsevier B.V., All rights reserved.

, SANHUEZA FRIGOLETT, JUAN MANUEL, DE LOS RIOS ESCALANTE, PATRICIO RENE, DIAZ HARRIS, RAMIRO JOEL, Sanhueza, Luís Manuel, Garrido, Karla, Celis, Freddy, García, Macarena, Cáceres, César, Moczko, Ewa, Díaz-Harris, Ramiro, J Aguirre, María, García, Camilo

Screen-printed electrodes (SPEs) have the advantage of being considered electrochemical cells that can be implemented in portable sensor applications. With the aim to improve the SPE performance, herein, we present different electrochemical surface modifications of carbon-based SPEs by cyclic voltammetry in hydrogen peroxide or sodium peroxide solution. SPEs were characterized using contact angle, Raman spectroscopy, laser-induced breakdown spectroscopy (LIBS), and electrochemical methods, including cyclic voltammetry (CV), electrochemical impedance spectroscopy, and square wave voltammetry (SVW). Main results agree with the observed changes by Raman spectroscopy and the sp2/sp3 ratio (I D/I G) of carbon vibrational bands. The diminishing of C2 Swan signal determined by LIBS suggests that the activation steps produced defects onto the working electrode in the SPE. Considering that the different intermolecular forces of the redox couples are useful to indirectly evaluate the different functional groups, the activated SPEs were studied in the presence of rutin and [Fe(CN)6]3?/[Fe(CN)6]4? redox couples. Main results show that the electrochemical response of the activated electrode surfaces can be properly used to improve the rutin electrochemical determination. Graphical Abstract: [Figure not available: see fulltext.] © 2023 Elsevier B.V., All rights reserved.

, SANHUEZA FRIGOLETT, JUAN MANUEL, Ruiz, Soledad, Jiménez-Bluhm, Pedro, Di Pillo, Francisca, Baumberger, Cecilia, Galdames, Pablo, Marambio, Victor, Salazar, Carla, Mattar, Cristián B., Sanhueza, Juan Manuel, Schultz-Cherry, Stacey L.

Although wild birds are considered the main reservoir of the influenza A virus (IAV) in nature, empirical investigations exploring the interaction between the IAV prevalence in these populations and environmental drivers remain scarce. Chile has a coastline of more than 4000 kilometres with hundreds of wetlands, which are important habitats for both resident and inter-hemispheric migratory species. The aim of this study was to characterize the temporal dynamics of IAV in main wetlands in central Chile and to assess the influence of environmental variables on AIV prevalence. For that purpose, four wetlands were studied from September 2015 to June 2018. Fresh faecal samples of wild birds were collected for IAV detection by real-time RT-PCR. Furthermore, a count of wild birds present at the site was performed and environmental variables, such as temperature, rainfall, vegetation coverage (Normalized Difference Vegetation Index (NDVI)) and water body size, were determined. A generalized linear mixed model was built to assess the association between IAV prevalence and explanatory variables. An overall prevalence of 4.28% ± 0.28% was detected with important fluctuations among seasons, being greater during summer (OR = 4.87, 95% CI 2.11 to 11.21) and fall (OR = 2.59, 95% CI 1.12 to 5.97). Prevalence was positively associated with minimum temperature for the month of sampling and negatively associated with water body size measured two months before sampling, and NDVI measured three months before sampling. These results contribute to the understanding of IAV ecological drivers in Chilean wetlands providing important considerations for the global surveillance of IAV. © 2021 Elsevier B.V., All rights reserved.

, SANHUEZA FRIGOLETT, JUAN MANUEL, Julliard, Paul Gabriel, Pascal, Simon, Siri, Olivier, Giorgi, Michel, Cortés-Arriagada, Diego, Sanhueza, Luís Manuel, Canard, Gabriel

A solventless and acid-catalyzed condensation of meso-perfluoroalkyl-dipyrromethanes with selected benzaldehydes was used to prepare ten different bilanes that were isolated before their oxidation into trans-A2B-corroles bearing two meso-perfluoroalkyl groups. Macrocycles bearing long chains (C3F7 or C7F15) are key precursors to afford ABC-corroles having a meso-acyl substituent when subjected to a mild and basic hydrolysis affecting one of the alkyl substituents. © 2024 Elsevier B.V., All rights reserved.

, SANHUEZA FRIGOLETT, JUAN MANUEL, Julliard, Paul Gabriel, Pascal, Simon, Siri, Olivier, Cortés-Arriagada, Diego, Sanhueza, Luís Manuel, Canard, Gabriel

Starting from pyrrole-carbinol derivatives, a set of three optimized experimental conditions was used to prepare six dipyrromethanes (DPM) bearing meso-poly-halogeno-alkyl chains. On the one hand, the condensation of p-anisaldehyde and the DPMs bearing a perfluoroalkyl chain (CF₃, C₃F₇ or C₇F₁₅) produced, after oxidation, the expected trans-A₂B₂-porphyrins in reasonable yields. On the other hand, 5,15-diformyl-10,20-diarylporphyrin was directly obtained starting from the meso-(dichloromethyl)dipyrromethane, while traces of an unprecedented porphyrin bearing two meso-acyl fluoride groups were isolated from the use of the meso-(chlorodifluoromethyl)dipyrromethane. The straightforward formation of bis-formyl porphyrins is competitive compared to previously reported methods and has been extended to other benzaldehydes. The electron-withdrawing character of the different substituents appended to porphyrins is enlightened through a combination of photophysical, electrochemical, structural and theoretical studies. © 2021 Elsevier B.V., All rights reserved.