The kinetics and stoicheiometry of silver(III) reduction by the octacyano-complexes of molybdenum(IV) and tungsten(IV)
作者:Edward T. Borish、Louis J. Kirschenbaum、Edoardo Mentasti
DOI:10.1039/dt9850001789
日期:——
The reactions of [Ag(OH)4]– with [Mo(CN)8]4– and [W(CN)8]4– involve an initial one-electron reduction of AgIII to AgII with second-order rate constants of 80 and 2.9 × 104 dm3 mol–1 s–1(25 °C, I= 1.2 mol dm–3), respectively. The tungstate reaction is quantitative with a stoicheiometry of 1 : 1. The reaction with [Mo(CN)8]4–, however, does not go to completion. There is apparently an equilibrium of
[Ag(OH)4 ] –与[Mo(CN)8 ] 4–和[W(CN)8 ] 4–的反应涉及具有二阶速率常数的Ag III到Ag II的初始单电子还原分别为80和2.9×10 4 dm 3 mol –1 s –1(25°C,I = 1.2 mol dm –3)。钨酸盐反应是定量的,化学计量比为1:1。与[Mo(CN)8 ] 4–的反应但是,并没有完成。显然存在氧化态的平衡。从平衡常数的值0.87 V的表观电位([OH - ] = 1.2摩尔分米-3,25℃)是估计的还原将[Ag(OH)4 ] -二聚的Ag II。初始的单电子氧化还原步骤的速率强烈相关ë中号/中号+为系列还原剂的[Fe(CN)6 ] 4-,的MnO 4 2-,[W(CN)8 ] 4-,和[Mo(CN)8 ] 4–。根据一般机理来解释结果,该机理涉及在初始氧化还原步骤之后的银(II)聚合。