渐进因子分析-分光光度法测定Fe^(3+)-SCN^-络合物的稳定常数

Determination of Stability Constants of IronC (Ⅱ)-thiocyanate Complex Using Evolving Factor Analysis and Spectrophotometry

本文利用渐进因子分析与化学平衡相结合的方法迭代求解逐级生成络合物的各级稳定常数。对Fe～(3+)-SCN～-体系在水溶液及50％丙酮溶液中的配体浓度-波长的两维双线性吸光度数据矩阵进行处理,求得水溶液中该络合物第一、二级稳定常数为 lgk_1=2.26,lgk_2=1.30。同时该法还可确定各种组分的存在区间及吸收光谱。本文还对丙酮的存在对Fe～(3+)-SCN～-络合物的影响作了研究,结果表明丙酮对高配位络合物具有明显的增敏增稳作用.

A method for determining the stability constants of mononuclear complexes has been developed by using chemical equlibrium combined with evolving factor analysis, and is used to treat the absorbdnce matrix of Fe3+-SCN- both in aqueous solution and 50% acetone solution. The first and second stability constants of the complex in aqueous are determined as lgk1 = 2. 26 and lgk2 = 1. 30, respectively. The method can also estimate the range of existence of each species, and provide the absorption spectrum of each species. The effect of acetone on the complex was investigated. It is found that acetone can enhance the stability and absorptivity of the complex with more ligands.