论文部分内容阅读
提出了研究Ｃｏ２＋ＯＨ２／Ｃｏ３＋ＯＨ２反应体系电子转移反应性的接触距离依赖关系的分析方案和ａｂ ｉｎｉｔｉｏ计算的应用方法，并讨论验证了此方案及其相应模型的可行性，分析了有关动力学量的接触距离依赖关系．详细的结果表明，用精确ＰＥＳ法得出的活化能与用非谐振子势得出的活化能吻合较好，它们明显优于谐势模型．对分布函数随接触距离从１．２０～０．３５ｎｍ改变而从１０－２变到１０－５．偶合矩阵元随接触距离的增加呈指数性降低．有效电子偶合要求接触距离＜０．７５ ｎｍ．在０．５０～０．７５ｎｍ范围内，相应的电子发射系数值在１．０～１０－６之间．电子因子使得定域ＥＴ速率也指数性的随接触距离的增加而降低，而对分布函数对总电子转移速率的贡献与电子因子的贡献则相反．球平均ＥＴ速率随接触距离的变化呈抛物线变化，并在接触距离为０．５ ｎｍ时有最大值．此最大值与总观测ＥＴ速率非常接近．对于此偶合体系，气态时ＥＴ速率是１０６Ｌ·ｍｏｌ－１·ｓ－１．进一步来说，实验上难于确定此类水合体系尤其是未饱和中间组分的电子结构和ＰＥＳ，ａｂｉｎｉｔｉｏ算法在讨论其ＥＴ反应性方面能起到一个有效的辅助作用．
The analytical scheme of the contact distance dependence of the electron transfer reactivity of Co2 + OH2 / Co3 + OH2 reaction system and the application of ab initio calculation are proposed. The feasibility of this scheme and its corresponding model is discussed and discussed. Distance dependency. The detailed results show that the activation energy obtained by the accurate PES method agrees well with the activation energy obtained by the non-harmonic oscillator potential, which is obviously better than the harmonic model. The distribution function changes with the contact distance from 1.20 ~ 0.35nm from 10-2 to 10-5. Coupling matrix elements decrease exponentially with increasing contact distance. Effective electron coupling requires contact distance <0.75 nm. In the range of 0.50 ~ 0.75nm, the corresponding electron emission coefficient is between 1.0 ~ 10-6. The electronic factor makes the localized ET rate also decrease exponentially with increasing contact distance while the contribution of the distribution function to the total electron transfer rate is opposite to the contribution of the electronic factor. The mean ET velocity of the sphere changes parabolically with the change of contact distance and has the maximum value at a contact distance of 0.5 nm. This maximum is very close to the total observed ET rate. For this coupled system, the gaseous ET rate was 106 L · mol-1 · s-1. Further, it is experimentally difficult to determine the electronic structure and PES of such hydrated systems, especially the unsaturated intermediate components, and the abinitio algorithm can play an effective auxiliary role in discussing its ET reactivity.