Metal ion-sulfur(IV) chemistry. 3. Thermodynamics and kinetics of transient iron(III)-sulfur(IV) complexes.
Metal ion-sulfur(IV) chemistry. 3. Thermodynamics and kinetics of transient iron(III)-sulfur(IV) complexes.
复制标题
DOI：
10.1021/es00173a006
复制
发表时间：
1988-08
影响因子：
11.4
通讯作者：
M. Conklin;M. Hoffmann
中科院分区：
文献类型：
--
作者：
M. Conklin;M. Hoffmann
用分光光度法测定了Fe(III)-S(IV)络合物在µ=0.4M时的稳定常数。得到了Fe^(3+)+SO3^(2-)⇌FeSO3^+的K1=10^(6.6)M^(-1)和FeOH^(2+)+SO3^(2-)⇌HOFeSO3的K4=10^(7.3)M^(-1)。拉曼测量表明，亚硫酸盐通过氧与金属结合。本文研究了Fe(III)与S(IV)之间的电子转移动力学，并提出了机理。根据这些结果，讨论了Fe(III)催化S(IV)自氧化反应的动力学和机理。
Stability constants for the formation of Fe(III)-S(IV) complexes at µ = 0.4 M were determined spectroscopically. Values of K_1 = 10^(6.6) M^(-1) for Fe^(3+) + SO_3^(2-) ⇌ FeSO_3^+ and K_4 = 10^(7.3) M^(-1) for FeOH^(2+) + SO_3^(2-) ⇌ HOFeSO_3 were obtained. Raman measurements indicate that sulfite binds to the metal through oxygen. The kinetics of electron transfer between Fe(III) and S(IV) have been studied, and a mechanism is proposed. Kinetic and mechanistic aspects of the Fe(III)-catalyzed autoxidation of S(IV) are discussed in light of these results.