光度法三元配合物组成的测定——合适参比溶液的选择

Spectrophotometric Determination of Compositions of Ternary Complexes——The Selection of Suitable Reference Solutions

三元配合物组成测定的多数方法来自二元体系,但不少对二元配合物很有成效的方法用于三元体系却受到种种限制。本文分析了其产生的原因,并根据不同的实际情况选用了不同的参比溶液,使经典的摩尔比法与连续变量法同样适用于三元体系。方法试用于Ti(Ⅳ)-5-Br-PADAP-H_2O_2三元体系,测得组成比为1:1:1。

Most of the methods for the determination of compositions of ternary complexes are derived from binary system. But some of the methods valid for binary complexes are invalid for ternary complexes. The main reason is that the absorbance measured is not proportional to the concentration of ternary complexes due to the interference of other species in the system. In this paper, suitable reference solutions have been selected to eliminate the interference. As a result, classical molar ratio method and continuous variation method may be usedconveniently and reliabely for determining the compositions of ternary complexes. This method has been used in Ti-5-Br-PADAP-H_2O_2 ternary system and the composition obtained is Ti: 5-Br-PADAP: H_2O_2=1: 1: 1.