Spectrophotometric determination of the stability constants of co(II) and DPKBH (di-2-pyridyl ketone benzoylhydrazone)

被引：9

作者：

Rossi, MV ^{[1
]}

SuarezIha, MEV ^{[1
]}

Hoffmann, MR ^{[1
]}

机构：

[1] CALTECH,WM KECK LABS,PASADENA,CA 91125

来源：

SPECTROSCOPY LETTERS | 1995年 / 28卷 / 08期

基金：

巴西圣保罗研究基金会; 美国国家科学基金会;

关键词：

stability constants; cobalt; di-2-pyridil ketone benzoylhydrazone; DPKBH;

D O I：

10.1080/00387019508009454

中图分类号：

O433 [光谱学];

学科分类号：

0703 ; 070302 ;

摘要：

In order to have more information about the thermodynamic properties of the complexes formed by Cobalt(II) and DPKBH (di-2-pyridyl ketone benzoylhydrazone) and for the development of speciation methods for cobalt, the respective stepwise formation constants were determined in ethanolic solution 50% (V/V), at pH 5.3 and 25.0 degrees C. The spectrophotometric method of corresponding solutions was used and the following overall formation constants were obtained: beta(1) = 5.305 x 10(6) M(-1) and beta(2) = 8.476 x 10(10) M(-2). The molar absorptivities of the 1:1 (epsilon(1)) and 1:2 (epsilon(2)) complexes (Co(II):DPKBH) were determined to be 4.475 x 10(3) and 2.994 x 10(4) (M(-1).cm(-1)), respectively. The calculated distribution diagram shows the percentage of the species at equilibrium as a function of the free DPKBH concentration.

引用

页码：1153 / 1166

页数：14

共 24 条

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