In Situ Generation of Organic Peroxide to Create a Nanotubular Uranyl Peroxide Phosphate

Abstract

Current synthetic pathways for uranyl peroxide materials introduce high initial concentrations of aqueous H2O2 that decline over time. Alternatively, in situ generation of organic peroxide would maintain constant concentrations of peroxide over prolonged periods of time and open new pathways to novel uranyl peroxide compounds. Herein, we demonstrate this concept through the synthesis of a nanotube-like uranyl peroxide phosphate (NUPP), Na12[(UO2)(μ-O2)(HPO4)]6(H2O)40, making use of the inhibited autoxidation of benzaldehyde in benzyl alcohol solutions in the presence of phosphonate ligands. The unique feature of NUPP is the bent dihedral angle U-(μ-O2)-U (123.9°±0.4° to 124.6°±0.5°), which allows hexameric uranyl peroxide macrocycles to adopt the nanotubular topology and prevents the formation of nanocapsules. Raman spectroscopy of the solution phase confirms our mechanistic understanding of the reaction pathway and confirms that consistent levels of peroxide are generated in situ over an extended period of time.