THE STABILITY OF COMPLEXES OF RE(Ⅲ ) ,U( Ⅵ) ,Th(Ⅳ)WITH HYDROXAMIC ACIDS

The stability constants of complexes of RE(Ⅲ),U(Ⅵ).Th(Ⅳ) with hydroxamic acids are determined by pH titration technique. The results show that with the same sort of hydroxamic acid,the order of stability is as follows:Yb>Tm>Tb>Eu>Gd>Sm>Y>Nd>Pr>Ce>LaWhen different hydroxamic acids react with the same metal-ion,the order of complex forming ability of dihydroxamic acid is higher than that of hydroxamic acid.