YouTube video by Prof Nicolas

This study centers on corrole, an emerging photosensitizer with great application potential, and innovatively develops an intelligent machine learning-based screening strategy. Through integrating molecular descriptor generation, feature engineering, multiple predictive models, and SHapley Additive exPlanations (SHAP)-based feature analysis, we have predicted two key performances of corrole photosensitizers, involving absorption peak wavelength and singlet–triplet intersystem crossing rate (kISC). Among 10 tested models, XGBoost outperforms other models. After introducing descriptors such as electronic structure and excited-state characteristics and conducting dimensionality reduction, its coefficient of determination is up to 0.87 for kISC prediction. SHAP analysis clarifies core design principles such as flat molecular structure, HOMO localization/LUMO delocalization and low surface electrostatic potential. The screened corrole with peripheral pyridyls, central nonmetallic P, and hydroxyls has excellent red light/NIR optical performance. Upon light irradiations, it exhibits a robust capacity for generating reactive oxygen species and enables the complete inactivation of cancer cells in vitro and in vivo. By leveraging fluorescence lifetime imaging, this corrole enables effective discrimination between normal cells and cancer cells. The intelligent screening strategy offers a novel paradigm for the efficient development of high-performance photosensitizers with distinct clinical translation potential.

We report the synthesis, crystal structure, and spectroscopic and computational electronic-structural characterization of two copper corroles, [Cu(5,15-bis(4-methylcarboxyphenyl)-10-(2-methylcarboxyphenyl)corrole)] (1Cu) and [Cu(5,15-bis(4-nitrophenyl)-10-(2-methylcarboxyphenyl)corrole)] (2Cu), as well as spectroscopic and computational studies on the corrole ligands (H3L1 and H3L2) in their neutral and anionic forms. We have found that the anionic corroles containing the 4-nitrophenyl substituents in positions 5 and 15 of the corrole ring show hypercorrole behavior, where the Q-bands are considerably more intense and red-shifted compared to those in the 4-methylcarboxyphenyl-substituted corroles. Electronic structure calculations using wave function methods (CASSCF/NEVPT2) reveal that the intense Q-bands, which extend slightly into the NIR region, are charge-transfer bands from the anionic corrole core to the strongly electron-withdrawing 4-nitrophenyl substituents. We further show that 2Cu can be reduced indirectly in the presence of excess F– or OH–, and the Q-band shifts toward the red in the polar environment containing the corresponding salts. Our study provides examples of easy-to-prepare anionic corroles, metalated and unmetalated, that show hypercorrole behavior and NIR absorption, and thus could find use in hyperthermal processes.