This paper examines the influence of aprotic solvents on the spectroscopic properties as well as the energy deactivation of two free-base corrole dyes substituted with C6F5 and/or 4-NO2C6H4 groups. Absorption, fluorescence and laser-induced optoacoustic spectroscopy have been used to follow the singlet and triplet states of fluorine corroles belonging to the A2B and A3 type in toluene (TL), chloroform (CL), dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and also in solvent mixtures. Changes in the absorption and fluorescence spectra are influenced by the type of solvent mixture. The fluorescence behaviors of the two investigated corroles were extremely different - fluorescence of the nitro-corrole in TL is dramatically quenched in the presence of DMF. In contrast, fluorescence quenching of fluorine corroles in DMF-TL mixtures is substantially weakened. Absorption, fluorescence, triplet population as well as singlet oxygen generation parameters are evaluated. The spectral experimental data are supported by quantum chemical calculations - time-dependent density functional theory (TD-DFT) and cyclic voltammetry experiments. The presented results are discussed from a viewpoint of aggregation, tautomerization, and deprotonation effects occurring in the corroles.
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http://dx.doi.org/10.1039/c5cp06335c | DOI Listing |
Sci Total Environ
January 2025
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan; Isotope Science Center, The University of Tokyo, Bunkyo, Tokyo 113-0032, Japan. Electronic address:
The adsorption reaction on clay minerals is crucial for understanding the environmental behavior of various cations, including cesium (Cs). However, its details remain unclear because of multiple adsorption sites of the clay minerals, a significant difference between concentrations in the atomic-scale experiments and the actual environment, and difficulties of evaluating bonding states of the adsorbed cations. It is expected that systematic experiments at the atomic-scale with a wide concentration range and application of density functional theory (DFT) calculations overcome the problems and bring crucial insights to link laboratory experiment results with environmental sample analysis.
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January 2025
Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
Healthcare-associated infections (HAI) are a critical public health problem, with 30 to 40% of infections related to the urinary tract system. These urinary tract infections (UTIs) are considered one of the most common microbial infections in hospital settings and everyday community contexts, where approximately 80% are highly correlated with urinary catheter insertion, i.e.
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January 2025
Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
The use of biomass feedstocks for producing high-value-added chemicals is gaining significant attention in the academic community. In this study, near-infrared carbon dots (NIR-CDs) with antimicrobial and bioimaging functions were prepared from branches and leaves using a novel green synthesis approach. The spectral properties of the synthesized NIR-CDs were characterized by ultraviolet-visible (UV-Vis) absorption and fluorescence spectroscopy.
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January 2025
Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences (MPI-NAT), Am Fassberg 11, 37077 Göttingen, Germany.
In a search for dyes photoactivatable with visible light, fluorenes with substituents at positions 2 and 7 were prepared, and their absorption and emission spectra were studied. In particular, the synthesis route to 9-diazofluorenes with 2-(N,N-dialkylamino) and N-modified 7-(4-pyridyl) substituents was established. These compounds are initially non-fluorescent, undergo photolysis with UV or blue light, and-in non-polar media-provide orange- to red-emitting products with a large separation between absorption and emission bands.
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January 2025
Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA.
Epigallocatechin gallate (EGCg), an abundant phytochemical in green tea, is an antioxidant that also binds proteins and complex metals. After gastrointestinal absorption, EGCg binds to serum albumin in the hydrophobic pocket between domains IIA and IIIA and overlaps with the Sudlow I site. Serum albumin also has two metal binding sites, a high-affinity N-terminal site (NTS) site that selectively binds Cu(II), and a low-affinity, less selective multi-metal binding site (MBS).
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