Imidazole-based tetrachloridoferrate(iii) magnetic ionic liquids: structural insights, photosensitizing potential, and selective anti-glioblastoma activity

Abstract

Tetrachloridoferrate-based ionic liquids represent an emerging class of functional materials with promising magnetic and biological properties, yet their potential as photosensitizers and anticancer agents remains underexplored. We report the synthesis of new imidazole-based tetrachloridoferrate(iii) salts and a comprehensive evaluation of their structural, magnetic, photochemical, and cytotoxic properties. The target ionic liquids were prepared through the quaternization of imidazole derivatives, followed by anion exchange with FeCl3. Structural analysis via single-crystal X-ray diffraction of selected compounds revealed distinct non-covalent interaction patterns and charge distribution governing stability, while magnetic measurements demonstrated weak antiferromagnetic exchange interactions along the tetrachloridoferrate chains. Furthermore, ESP experiments revealed efficient photosensitized singlet oxygen generation under UV irradiation, which correlates with photodegradation of bisphenol A. Biological evaluation across a broad panel of solid and haematological cancer cell lines identified remarkable, selective cytotoxicity toward the LN229 glioblastoma cell line, with IC50 values as low as 0.70–1.50 µM, while no significant activity was observed against other glioblastoma models or normal PBMCs. These findings highlight imidazolium tetrachloridoferrates as compelling candidates for further investigation in oxidative-stress-based anticancer strategies.