Herein, we report the synthesis of eight 5-substituted-3-methyl-4-nitroisoxazoles with styryl structures (B1–B8) characterized by ¹H NMR, ¹³C NMR, FT-IR, HRMS, and XRD. Their optical properties were evaluated using UV-vis and fluorescence spectroscopy, electrochemical behavior via cyclic voltammetry, and electronic structure and nonlinear optical (NLO) properties using density functional theory (DFT) calculations. The compounds were obtained in yields ranging from 19% to 96%, with B4 and B8 being reported for the first time. Electrochemical analysis revealed quasi-reversible redox behavior, indicating chemical stability and efficient charge transfer. Notably, the low reducibility of the nitro group in B7 minimizes the formation of reactive species and enhances excitonic recombination and emission efficiency, supporting its application in functional OLEDs. All compounds exhibited strong NLO responses owing to their D–π–A configurations, with β values ranging from 71.59 to 379.95 esu and γ values from 218.02 to 1789.03 esu, significantly surpassing urea. Additionally, their high thermal stability (>200 °C) reinforces their potential for applications in optics, photonics, and optoelectronic devices, highlighting their suitability for light-emitting technologies and high-performance NLO systems.

Correction for ‘Optoelectronic and NLO potential of styryl-functionalized nitroisoxazoles for OLED technologies’ by Karen Acosta-Quiroga et al. , J. Mater. Chem. C , 2025, 13 , 9083–9098, https://doi.org/10.1039/D5TC00619H.

In this study, four quinoline–based chromophores (EP01–EP04) with distinct π–conjugated architectures were studied to understand how molecular connectivity influences their electronic structure and nonlinear optical properties. Experimental characterization was combined with DFT and TD–DFT calculations to relate molecular structure to UV–Vis absorption, frontier–orbital distribution, and calculated electronic response. EP01, which contains a vinylene bridge connecting quinoline to an alkoxy–substituted aromatic ring, exhibited the smallest HOMO–LUMO gap in the series (5.65 eV) and the most red–shifted experimental absorption in methanol (353 nm). In comparison, the principal absorption maximum of EP02 occurred at 265 nm. The results for EP03 and EP04 showed that band position and intensity depend not only on the HOMO–LUMO gap but also on the orbitals involved in each transition. The calculated solvent effect on the most intense transitions was limited, with shifts of 2–7 nm between toluene and water. EP01 also exhibited the largest calculated first and second hyperpolarizabilities, approximately 2.58 and 2.92 times those of EP02, respectively. Together, these findings show that connecting the aromatic fragments through a continuous π–pathway favors the optical response of these derivatives and provides structural guidance for designing new quinoline–based chromophores.

Background/Objectives: Chagas disease is endemic to 21 Latin American countries and is a great public health problem. Current chemotherapy remains unsatisfactory; consequently, the need to search for new drugs persists. The aim of this work is to develop a machine learning computational model, which allows the identification of new chemical compounds with potential trypanosomicidal activity. Methods: A large dataset of 584 compounds, obtained from the Drugs for Neglected Diseases initiative, is used to develop the computational model. AlvaDesc v3.0.14 software is used to calculate the molecular descriptors, and Scikit-learn of Python to obtain the random forest. Results: The best random forest model shows accuracy of 82.1% for the training set and near to 79% for the test set, achieving specificity values over 84.9%, and the false alarm rate values were almost under 15% for both sets. As an experiment of virtual lead generation, the present model is finally satisfactorily applied to the virtual evaluation of a series of 1,2-disubstituted nitroindazolin-3-ones obtained a good agreement between the predicted activity and the experimental assays performed. Compounds 1c and 2c stood out as the most active in the series, with half-maximal inhibitory concentration (IC₅₀) values of 71.3 and 40.9 μM, respectively. Mechanistic analyses suggest that the presence of the nitro group may promote the generation of reactive oxygen species through enzymatic redox activation, potentially involving T. cruzi nitroreductases (TcNTRs), leading to oxidative-stress-mediated parasite death. For the most active compounds, the data are consistent with intracellular hydroxyl radical generation through enzymatic redox processes. Conclusions: Even though none of them resulted more active than nifurtimox, the current results constitute a step forward in the search for efficient ways to discover new lead antitrypanosomals.