论文标题
空间影响对氢原子转移反应的作用
The role of steric effects on hydrogen atom transfer reactions
论文作者
论文摘要
我们探索了空间影响如何影响草基和烷烃之间的氢原子转移(HAT)反应的速率。过渡态的量子化学计算表明,激活屏障和反应焓都受自由基上笨重的取代基的影响,但较少受烷烃上的取代基的影响。激活屏障与反应焓通过Evans-Polanyi的关系相关,即使空间效应很重要。在某些情况下,分散效应可以另外稳定过渡状态。
We explored how steric effects influence the rate of hydrogen atom transfer (HAT) reactions between oxyradicals and alkanes. Quantum chemical computations of transition states show that activation barriers and reaction enthalpies are both influenced by bulky substituents on the radical, but less so by substituents on the alkane. The activation barriers correlate with reaction enthalpies via the Evans-Polanyi relationship, even when steric effects are important. Dispersion effects can additionally stabilize transition states in some cases.