Sonolysis of actinide(IV) β-diketonates in alkanes

Abstract

Ultrasonic irradiation with the frequency of 20–22 kHz and absorbed acoustic power about 0.4 W ml –1 causes degradation of An(IV) tetrakis-β-diketonates, AnL 4, where An(IV) is Th(IV), Np(IV), and Pu(IV), and HL is hexafluoroacetylacetone (HFAA) and dibenzoylmethane (HDBM), in hexadecane solutions in the presence of argon. The rate of the sonochemical process corresponds to a first-order kinetic law with respect to metal β-diketonate concentrations. The first-order rate constant of sonolysis increases with the increase in the volatility of the metal complexes. Solid sonication products consisted of a mixture of actinide carbides and partial degradation products, PDP, of initial metal β-diketonates. It is assumed that metal carbides are formed within the cavitating bubbles as a result of high-temperature process with participation of actinide(IV) β-diketonates and solvent vapours. PDP formation is attributed to the thermolysis of the complexes in a liquid reaction zone surrounding the cavitating bubble. To cite this article: S.I. Nikitenko et al., C. R. Chimie 7 (2004) .