邻菲罗啉及其衍生物萃取Fe(Ⅱ)机理的电化学研究

本文应用电流扫描极谱法及计时电位法,对邻菲罗啉及其衍生物萃取Fe~(2+)的机理进行了探讨。认为是萃取剂从有机相中扩散到水相中,与Fe~(2+)形成配合物。出现的双波是由于配合物及萃取剂质子化后迁移的结果。证明了配合物迁移波是动力学控制的,萃取剂质子化波是由萃取剂扩散所控制的。求出了配求出其K_f=(3.75 1.65位比为:Fe~(2+)(萃取剂)=1:3。对于决速步骤:求出其K_f=(3.75±1.65)×10~6 1·mol~(-1)s~(-1)。

ELECTROCHEMICAL STUDYING OF TRANSFER FACILITATED OF FERROUS ION BY PHENANTHROLINE AND ITS DERIVATIVES

In this paper, the mechanism of extraction of ferrous ion by phcnanthrolinc and its derivatives was studied by Current Scan Polarography and Chronopotcntiomctry. Results showed that the cxtractant diffuses from organic to aqueous phase and forms complex ion with ferrous ion. But for DMphen, complex ion with ferrous can not be formed because of stcric hindrance effects. Double waves were observed. One is ascribed to the facilitated transfer by extractant and the another is the charge transfer of protonatcd transfer by cxtractants. The former is controlled by kinetics, and later by the diffusion of extractant. The stiochiomctry of the complex ion can be calculated by the relations between, the limiting current of different waves, and the results showed the ratio of Fe: L(cxtractant) is 1:3. For the kinetic rate-dctcrming step