Structure of surface films of malonate mono- and dinitroxyl methanofullerenes

An effect of aqueous subphases composition on the character of change of the bilayer structure of malonate mono- and dinitroxyl methanofullerenes surface films has been established. Their transformation to monolayers takes place in the presence of hydroxy-containing compounds (quercetin, dihydroquercetin, 4-methylphenol, ascorbic acid, as well as in a buffer mixture with pH 10). A loosening of mixed films on the basis of nitroxyl methanofullerenes in the presence of compounds affecting radical processes (2,4,6-tri( tert -butyl)phenol, 2-methyl-3-nitrosopropane, and TEMPO) has been demonstrated. The character of compression isotherms π = f ( A 0 ) (π is a surface pressure, A 0 is an effective molecular area of methanofullerene) of the mixed films on water depends on the nature of component incorporated and the reaction time in solution: in all the cases, A 0 increased almost 2-fold, to 1.05 nm 2 molecule −1 , whereas a compressibility parameter β decreased 2–3-fold, to (1–2)·10 17 N m −3 . Visualization of the thin film surfaces (atomic force spectroscopy) showed that a decrease of parameter β in the Langmuir layers corresponds to the particle aggregation and structurization of the films.