Vol 63, No 13 (2018)

On the basis of the currently available uranyl complexes with hydroxylamine and its N-substituted derivatives and oximes, the coordination modes of the ligands and structural features of such complexes have been considered with the aim of determining general trends for this new family of uranium(VI) compounds. All the uranyl oximate and hydroxylaminate complexes contain a deprotonated ligand coordinated to the central atom through the nitrogen and oxygen atoms to form a stable three-membered chelate ring. Depending on the composition, these compounds can be divided into two large groups: complexes with tris(chelate) and bis(chelate) structural moieties.

Water–electrolyte systems comprising aqueous solutions of nitrates, iodates, sulfates, acetates, orthophosphates, chlorides, and fluorides of Group I–III metals, transition metals, and lanthanides were studied. Studies of glass formation in the system Al₂(SO₄)₃–H₂O serve as an example to give an idea of the original method for studying water–electrolyte glass-forming solutions and glasses developed at the Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, enabling one to predict their structures. This investigation method and analysis of experimental data have no analogues either in Russia or abroad. The results obtained were used to elucidate general glass formation trends in various water–electrolyte systems. We were the first to prove a polymeric structure of glass-forming compositions in some water–electrolyte systems. We were also the first to combine the glasses of water–electrolyte systems in a special class of glasses that are hydrogen-bonded polymeric items.

The views of different authors on equilibria in solutions of fluorosilicic acid are discussed. The model of the aid as an equilibrium system involving hexacoordinated complexes [SiF_6–n(H₂O)_n]^n–2 (n = 0–2) is believed to be the most adequate.