Abstract
Europium (III) was extracted into chloroform with pivaloyltrifluoroacetone (1,1,1-trifluoro-5,5-dimethyl-2,4 hexanedion, PTA) and 2,2'-bipyridyl (2,2'-bpy) or with PTA and 4,4'-bipyridyl (4,4'-bpy). By combining the extractants, the extraction was improved, although the enhancement with PTA and 2,2'-bpy was much larger than that with PTA and 4,4'-bpy (the distribution ratio in the presence of 10-2 M 2,2'-bpy was enhanced by a factor of almost 104, while that in the presence of 10-2 M 4,4'-bpy was as high as 10 times, compared to the distribution ratio in the extraction with PTA, itself, reflecting the function of the bidentate (2,2'-bpy) and the monodentate (4,4'-bpy). In addition, the extracted species with PTA and 4,4'-bpy were accompanied by four PTA and one 4,4'-bpy, EuA3 · HA · B as well as EuA3, EuA3 · B and EuA3 · 2B. As the extracted species of lanthanoids (III) with β-diketone and a monodentate Lewis base, such as tributylphosphate, EuA3, EuA3 · B and EuA3 · 2B were reported before. The extraction as EuA3 · HA · B may reflect that the Lewis basicity of 4,4'-bpy is similar to that of PTA.
