芳香族羟肟的合成及其萃取铜的结构-性能研究

Synthesis of Aromatic Hydroxyoximes and their Structure-Reactivity Studies in Copper Extraction

合成了一系列不同结构高纯度的芳香族羟肟,测得了它们的反式羟肟含量和解离常数,用HMO法计算了配位原子的电荷密度,并用多元线性回归法研究了这类化合物的结构参数与其萃取铜反应平衡常数的关系。

In this paper we described the method of synthesis of a series of pure aromatic hydroxyoximes with known concentration of anti-forms and the identity of the compounds was checked by thin-layer chromatography, elemental analyses, IR, UV and ~1H NMR, As structure parameters, besides pK_a, the charge density of phenolic oxygen and oximido-nitrogen were taken based on HMO calculation. Both distridution ratio and reaction constant in copper extraction served as parameter representing extraction capability. On these bases the relationship between chemical structure and extraction properties of aromatic hydroxyoxime in copper extraction was evaluated. In contrast with literature data our experimental results demonstrated that no apparent influence was found between pK_a and reaction constant. Meanwhile, both charge density of phenolic oxygen and oximido-nitrogen play an extremely important role in copper extraction by aromatic hydroxyoximes. These structural effects were rationalized by formation of stable square planar coordination compound.