Lutetium complexes hydrolysis

Separation Processes. The product of ore digestion contains the rare earths in the same ratio as that in which they were originally present in the ore, with few exceptions, because of the similarity in chemical properties. The various processes for separating individual rare earth from naturally occurring rare-earth mixtures essentially utilize small differences in acidity resulting from the decrease in ionic radius from lanthanum to lutetium. The acidity differences influence the solubiUties of salts, the hydrolysis of cations, and the formation of complex species so as to allow separation by fractional crystallization, fractional precipitation, ion exchange, and solvent extraction. In addition, the existence of tetravalent and divalent species for cerium and europium, respectively, is useful because the chemical behavior of these ions is markedly different from that of the trivalent species. 

The hydroxo complexes (3a)2Ho(OH) and (3a)2Er-(OH), reported by C. Qian et al., were formed from the respective chloro complex and trace amounts of water present in the solvent. The lutetium analogue has been suggested as the final product of the hydrolysis of (3a)2LuCl, which was investigated by IR spectroscopy. The related yttrium compound 9aY(OH) was obtained by H. Schumann et al. from... 

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