Linear Free Energy Relationships in Electrostatic Catalysis
Linear Free Energy Relationships in Electrostatic Catalysis
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DOI：
10.1021/acscatal.2c02234
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发表时间：
2022-06-27
期刊：
影响因子：
12.9
通讯作者：
Berkelbach, Timothy C.
中科院分区：
文献类型：
--
作者：
Hoffmann, Norah M.;Wang, Xiao;Berkelbach, Timothy C.
利用电场来改变化学反应是催化领域一项有前景的新兴技术。然而，指导原则很少，合理的设计需要对过渡态的假设或显式的原子计算。在这里，我们提出了一种在物理有机化学和催化的其他领域中很常见的线性自由能关系，它在微观上将场引起的活化能变化与反应能变化联系起来，将动力学和热力学行为联系起来。我们使用对称 S(N)2 反应和金表面芳基卤化物脱卤的第一性原理电子结构计算来验证我们的理论，并观察线性自由能关系的特征，例如向早期和晚期过渡态的转变。我们还报告并解释了一种违反直觉的情况，其中与活化能和反应能相关的比例常数为负，因此稳定产物会增加活化能，即与贝尔-埃文斯-波兰尼原理相反。
The use of electric fields to modify chemical reactions is a promising, emerging technique in catalysis. However, there exist few guiding principles, and rational design requires assumptions about the transition state or explicit atomistic calculations. Here, we present a linear free energy relationship, familiar in other areas of physical organic chemistry and catalysis, that microscopically relates field-induced changes in the activation energy to those in the reaction energy, connecting kinetic and thermodynamic behaviors. We verify our theory using first-principles electronic structure calculations of a symmetric S(N)2 reaction and the dehalogenation of an aryl halide on gold surfaces and observe hallmarks of linear free energy relationships, such as the shifting to early and late transition states. We also report and explain a counterintuitive case, where the constant of proportionality relating the activation and reaction energies is negative, such that stabilizing the product increases the activation energy, that is, opposite of the Bell-Evans-Polanyi principle.