ABOUT THE EXISTENCE OF TH(III) IN AQUEOUS-SOLUTION

Recently [1] it was claimed that (i) the reaction of ThCl4 with HN3 in slightly acidic aqueous solution produces the aqueous ion of Th(III) according to the thermodynamically-allowed reaction: Th4+ + HN3 --> Th 3+ + 1.5N(2) + H+; (ii) Th(III) was identified by its absorption (UV-v is. 200-1300 nm) and ESR spectra. This paper is aimed to prove that th e aqueous ion Th3+ (ag) is thermodynamically unstable and that the ide ntification of Th(III) in the considered solutions ask for new experim ents. (C) 1998 Elsevier Science Ltd. All rights reserved.