摘要
报道了6个具有不同烷基结构的新型中性双配位有机磷萃取剂——二烷氧基膦酰乙酸酯(R_1O)_2PO-CH_2-CO-OR_2对镧系元素的萃取性能和规律。该类萃取剂中二个配位基团P=O和C=O附近的酯烷基R_1和R_2的结构变化明显地影响其对镧系元素的萃取能力,分配系数随着镧系元素原子序数的增大而呈双峰效应,萃取机理与一般中性溶剂化络合萃取相似。萃取配台物中镧系元素与配体的摩尔比为1:3,并用元素分析、分子量测定和红外光谱对二丁氧基膦酰乙酸异丙酯与硝酸镧配合物进行了研究。
The structure and reactivity studies on the extraction of lanthanides by six dialkyl alkoxycarbonylmethanephosphonates with various alkyl groups are described. The steric effect shows obvious influence on the behaviour of dialkyl alkoxycarbonylmethanephosphonate in the lanthanide extraction. There are two peaks in the extraction curve of lanthanide. The extraction increases with the increasing of atomic number from La to Eu, but decreases at Gd, and increases again with the atomic number thereafter. There is another peak at Dy. The extraction mechanism studied by slope method is similar to that for normal neutral solvent complex extraction. The composition of the extracted coordination compound is Ln:L=1:3, where Ln=La, Dy, Lu and L=(R,O)_2—CH_2—OR_2.The elemental analysis and molecular weight determination of the coordination compound formed by La(NO_3)_3 and (C_4H_9O)_2—CH_2—OC_3H_7(i) give the same conclusion. The IR absorption spectra of the dialkyl alkoxycarbonylmethanephosphonate complexes with the nitrate of lanthanide are investigated. We have shown that the P=O is the primary donor and the carbonyl group involves partly in the coordination.
出处
《中国稀土学报》
CAS
CSCD
北大核心
1989年第1期39-43,共5页
Journal of the Chinese Society of Rare Earths
