稀土(Ⅲ)、铀(Ⅵ)和钍(Ⅳ)-异羟肟酸配合物的稳定性

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

摘要: 报道了用pH滴定法所测得的几种异羟肟酸与稀土(Ⅲ)、铀(Ⅵ)和钍(Ⅳ)形成的配合物的稳定常数。结果表明,稀土(Ⅲ)离子所形成配合物的稳定性大小顺序为:Yb>Tm>Tb>Eu>Gd>Sm>Y>Nd>Pr>Ce>La。钍(Ⅵ)的异羟肟酸配合物的稳定性比铀(Ⅵ)好。对于同一种金属离子,不同配体的络合能力是:DDHA>SHA>OXHA>OPHA>NEHA>BHA>EHA,且二酰异羟肟酸配合物的稳定性大于相同碳原子数的单酰异羟肟酸的配合物。

Abstract: 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.