The synthesis and characterisation of a homologous series of quinoid sulfur-containing imidazolyl-substituted heteroacenes is described. The optoelectronic and magnetic properties were investigated by UV/vis, fluorescence and EPR spectroscopy as well as quantum-chemical calculations, and were compared to those of the corresponding benzo congener. The room-temperature and atmospherically stable quinoids display strong absorption in the NIR region between 678 and 819 nm. The dithieno[3,2-b:2',3'-d]thiophene and the thieno[2',3':4,5]thieno[3,2-b]thieno[2,3-d]thiophene derivatives were EPR active at room temperature. For the latter, variable-temperature EPR spectroscopy revealed the presence of a thermally accessible triplet state, with a singlet-triplet separation of 14.1 kJ mol .
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9314731 | PMC |
http://dx.doi.org/10.1002/chem.202200478 | DOI Listing |
Membranes (Basel)
December 2024
Institute of Physics, Opole University, Oleska 48, 45-052 Opole, Poland.
This article investigates the influence of dopant molecules on the structural and dynamic properties of lipid bilayers in liposomes, with a focus on the effects of dopant concentration, size, and introduced electric charge. Experimental studies were performed using electron paramagnetic resonance (EPR) spectroscopy with spin probes, complemented by Monte Carlo simulations. Liposomes, formed via lecithin sonication, were doped with compounds of varying concentrations and analyzed using EPR spectroscopy to assess changes in membrane rigidity.
View Article and Find Full Text PDFmBio
December 2024
School of Medicine, Department of Pathology, Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA.
The bacterium responsible for Lyme disease, , accumulates high levels of manganese without iron and possesses a polyploid genome, characteristics suggesting potential extreme resistance to radiation. Contrary to expectations, we report that wild-type B31 cells are radiosensitive, with a gamma-radiation survival limit for 10 wild-type cells of <1 kGy. Thus, we explored radiosensitivity through electron paramagnetic resonance (EPR) spectroscopy by quantitating the fraction of Mn present as antioxidant Mn metabolite complexes (H-Mn).
View Article and Find Full Text PDFMol Pharm
December 2024
Pharmaceutical Technology and Biopharmaceutics, Department of Pharmacy, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany.
There is still an insufficient understanding of how the characteristics of protein drugs are maintained in the solid state of lyophilizates, including aspects such as protein distances, local environment, and structural preservation. To this end, we evaluated protein folding and the molecules' nearest environment by electron paramagnetic resonance (EPR) spectroscopy. Double electron-electron resonance (DEER) probe distances of up to approximately 200 Å and is suitable to investigate protein folding, local concentration, and aggregation, whereas electron spin echo envelope modulation (ESEEM) allows the study of the near environment within approximately 10 Å of the spin label.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
School of Chemical Engineering and Technology, Guangdong Industry Polytechnic University, Guangzhou, China.
In subsurface water, humic acid (HA) can react with active chlorine to form carcinogenic compounds, posing ecological issues and health risks. This study aims to create sludge activated carbon (SAC), combine it with Fe, and activate peroxosulfate (PMS) to remove HA from water. To verify the successful modification of SAC, the physicochemical properties were characterized using various methods such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer Emmett Teller (BET) analysis, and X-ray photoelectron spectroscopy (XPS).
View Article and Find Full Text PDFInorg Chem
December 2024
Department of Chemistry, Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden.
The reduction of stable trivalent lanthanide species (Ln(III)) by the excited states of organic chromophores is the basis of photocatalytic divalent lanthanide-mediated reduction reactions. While indirect evidence of the photochemical formation of the reactive Ln(II) species is abundant, direct spectroscopic evidence of their presence is scarce. Here, nine chromophores with absorptions covering the near UV and visible ranges were systematically investigated in the presence of Ln(III) ions to evaluate their ability to reduce Eu(III) upon excitation with visible light to the catalytically active Eu(II) species.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!