Uranyl nitrato complexes

The uranyl nitrato and acetato anionic complexes are similar. From low acid 5M metal nitrate 14) or acetate solutions the relative ratios of U02(N03)4- to U02(N03)3 and U02(C2H302)4 to U02(C2H302)3 in the resin phase closely reflect the difference in formation constants of the tetra complexes from the tri complexes. This is despite the fact that the formation constants of the triacetate complex and the trinitrate complex from the respective lower complexes are obviously different and the aqueous phase contains mainly anionic species in the acetate case but essentially no anionic species in the nitrate case (14). 

Bums, J.H. 1983. Solvent-extraction complexes of the uranyl ion. 2. Crystal and molecular structures of cafe a-Bis( r-di- -butyl phosphato-0,0 ) dioxouranium(VI) and Bisfp-di-n-butyl phosphato-O, O )bis[(nitrato)(tn-n-butylphophine oxide) dioxouranium(VI)]. Inorg. Chem. 22 1174—1178. 

Uranyl nitrate substantially increases the distribution coefficient Die- "Ihis was explained by the formation of a mixed nitrato-pertcchnetato-TBP complex of UOl" [121,122] according to the equilibrium ... 

The 0x0 (0 ) ligand is dominant in the coordination chemistry of osmium, participating in the VIII to IV oxidation states inclusive. The tetroxide OSO4 is the single most important compound of osmium OSO4 and the recently discovered [0s04] ion arc tetrahedral. The /ra 5-[0=0s —O] osmyl moiety displays an extensive chemistry, comparable with that of the uranyl 0=U=0 unit, and there is an extensive and unique cyclic oxo-ester chemistry (p. 584). There is surprisingly little information on hydroxo, aqua, sulfato, nitrato or phosphato complexes, but much recent work has been carried out on carboxylato species, and clearly much work remains to be done on the O-donor chemistry of the element. There are a reasonable number of sulfur-donor complexes but few with selenium or tellurium. 

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