非水溶剂中稀土离子和穴醚（2．2）配合物的电导研究

A Conductance Study of Complexes of Rare Earth with Cryptand (2.2) in Nonaqueous Solvents

用电导法研究了２５℃时，硝酸稀土和穴醚（２．２）在不同溶剂中的配位行为．计算了１∶１配合物的稳定常数及摩尔电导率．在非水溶剂（ＣＨ３）２ＣＯ·ＣＨ３ＣＮ·ＣＨ３ＯＨ和ＤＭＦ中，由于配位过程中伴随着Ｌｎ（Ⅲ）离子的溶剂化作用，稀土和穴醚（２．２）配合的的稳定常数随Ｌｎ原子序数的增加而变化不大．同一稀土穴醚配合物在不同非水溶剂中的摩尔电导（Λ）值大小顺序为ＤＭＦ＞ＣＨ３ＯＨ＞ＣＨ２ＣＮ＞（ＣＨ３）２ＣＯ．

The coordination reaction of several rare earth nitrates with cryptand (2.2) in (CH 3) 2CO, CH 3CN, CH 3OH and DMF at 25 ℃ has been studied by means of using conductometric titration. The stability constants and the molar conductivities for the 1∶1 coordination compounds were calculated. Since the complexation is accompanied by solvation of the Ln(Ⅲ) ion in nonaqueous solvents, for lanthanide series, there is more or less variation in stability constants of complexes of rare earth with cryptand (2.2) when atomic numbers increas. The orders of the Λ ML(NO 3) 3 values about the same rare earth crown ether complexes in these nonaqueous solvents are DMF>CH 3OH>CH 3CN>(CH 3) 2CO .