This study presents an analysis of a set of iron oxides nanoparticles (NPs) (γ-Fe₂O₃, α-FeOOH, δ-FeOOH, 5Fe₂O₃·9H₂O, and Fe₃O₄) as potential candidates for ferroptosis therapy in terms of a phase state, magnetic characteristics, and the release of Fe^2+/Fe³⁺ as ROS mediators. Due to the values of saturation magnetization for Fe₃O₄ (31.6 emu/g) and γ-Fe₂O₃ (33.8 emu/g), as well as the surface area of these particles (130 and 123 m²/g), it is possible to consider them as promising magnetically controlled carriers that can function with various ligands. The evaluation of the release of Fe²⁺/Fe³⁺ ions as catalysts for the Fenton reaction showed that the concentration of the released ions increases within first 3 h after suspension and decreases within 24 h, which probably indicates desorption and adsorption of ions from/onto the surface of nanoparticles regardless their nature. The concentration of ions released by all nanoparticles, except α-FeOOH-Fe²⁺, reached 9.1 mg/L for Fe³⁺ to 1.7 mg/L for Fe²⁺, which makes them preferable for controlling the catalysis of the Fenton reaction. In contrast, a high concentration of iron ions to 90 mg/L for Fe³⁺ and 316 mg/L for Fe²⁺ released from compound α-FeOOH-Fe²⁺ allows us to utilize this oxide as an aid therapy agent. Results obtained on iron oxide nanoparticles will provide data for the most prospective candidates that are used in ferroptosis-inducing systems.

Photochemical properties of symmetrical pyromellitic diimide containing two cymantrenyl fragments at two nitrogen atoms were studied with IR, NMR, UV-vis, ESI-MS, and cyclic voltammetry. It was found that new unstable chelates are formed during photolysis. At the same time, the CO ligand dissociates from two Mn(CO)₃ fragments during photoexcitation, which dramatically changes the electronic and redox properties of the molecule compared to the cymantrene derivative containing one imide fragment. Photolysis leads to a color change from light yellow to green. DFT calculations confirmed the possibility of the formation of complexes due to the loss of one or two CO ligands from manganese atoms. The results obtained with variation of photolysis conditions demonstrated the hemilabile character of the Mn-O=C(imide) bond. On addition of external ligands, the color and electrochemical properties changed, which is promising for the use of this complex as a sensor for small molecules.