Isotope Effects in Oxidation-Reduction Reaction

汞合金电解被认为是研究氧化还原反应中同位素效应最合适的体系。选择了钾、铷、镁、钡等元素，实验研究了这些元素在不同温度下的同位素效应。重点讨论了温度对两相间同位素分布或同位素分离系数的影响。在钾和钡的汞齐电解过程中观察到两种类型的同位素效应；动力学同位素效应和平衡同位素效应。在动力学过程中，当两相之间存在净传质时，较轻的同位素在传质方向上的运动速度较快。在平衡状态下，浓度没有变化，较重的同位素可能在实验温度区域的汞合金相中分馏。锂（已报道）、铷和镁在平衡态的同位素效应不同；较轻的同位素在汞合金相中分出，然而，非常有趣的是，下面的方程适用于本工作中考虑的所有汞合金同位素平衡效应：epsilon=A/T+B/T^2

Amalgam electrolysis was investigated as the most appropriate system for the research into the isotope effects in oxidation-reduction reactions. The elements of potassium, rubidium, magnesium and barium were selected and the isotope effects of these elements were experimentally studied at different temperatures. Attention was placed on the temperature effects of the isotopic distribution between two phases or the isotope separation coefficient.Two types of the isotope effects have been observed in the amalgam electrolytic processes of potassium and barium ; kinetic isotope effects and equilibrium isotope effects. In kinetic process, where there exists a net mass transfer between two phases, lighter isotope moves faster the other in the direction of the mass transfer. In equilibrium state, where there is no change in the concentrations, heavier isotope is likely fractionated in the amalgam phase in the experimental temperature region. The isotope effects lithium (reported) , rubidium and magnesium in the equilibrium state are different ; lighter isotope is fractionated in the amalgam phase, however, it is very interesting that the following equation is applicable to all amalgam isotope effects in equilibrium considered in the present work.epsilon=A/T+B/T^2