高位阻有机磷萃取剂的研究 Ⅲ.叔丁基膦酸单烷基酯的合成及其结构与萃取镱、镥性能的关系

STUDIES ON HIGHLY STERICALLY HINDERED ORGANOPHOSPHORUS EXTRACTANTS Ⅲ. SYNTHESIS OF MONOALKYL t-BUTYLPHOSPHONATES AND RELATIONSHIP BETWEEN THEIR STRUCTURES AND EXTRACTION BEHAVIOUR ON Yb(Ⅲ), Lu(Ⅲ)

合成了一系列具有高位阻特征的叔丁基膦酸单烷基酯t-C_4H_9P(O)(OR)OH(R分别为n-C_8H_(17),—CH_2CH(C_2H_5)C_4H_9,—CH(CH_3)C_6H_(13),—CH_3CH_2CH(CH_3)CH_2C(CH_3)_3和n-C_(12)H_(25))。初步探讨了它们的结构与萃取重稀土元素Yb(Ⅲ)和Lu(Ⅲ)性能的关系。萃取能力随着酯烷基空间位阻的增大而显著降低。在ph_(1/2)值与酯烷基的Charton空间参数v间存在着近似的直线关系。叔丁基膦酸单烷基酯对Yb、Lu的反萃性能优于2-乙基己基膦酸单2-乙基己酯(P-507)。

A new series of monoalkyl t-butylphosphonates (MAtBP) with highly steric hindrance, t-C_4H_9P(O)(OR)OH, where R represents n-C_5H_(17),—CH_2CH(C_2H_5)C_4H_9,—CH(CH_3)C_6H_(13),—CH_2CH_2CH(CH_3)CH_2C(CH_3)_3 and n-C_(12)H_(25), respectively, were synthesized and the relationship between their structure and extraction behaviour on Yb(Ⅲ), Lu(Ⅲ)Was investigated. Their extraction ability markedly decreases with the increase of the steric hindrance from ester alkyl group. There is an approximate linear correlation between pH_(1/2) values and Charton steric parameter v of the ester alkyl groups. The stripping behaviour of Yb, Lu with MAtBP is superior to that with mono-2-ethylhexyl 2-ethylhexylphosphonate (P-507).