Spin-Forbidden Reactions: Adiabatic Transition States Using Spin-Orbit Coupled Density Functional Theory
Spin-Forbidden Reactions: Adiabatic Transition States Using Spin-Orbit Coupled Density Functional Theory
复制标题
DOI：
10.1002/chem.201704608
复制
发表时间：
2018-04-06
影响因子：
4.3
通讯作者：
Belanzoni, Paola
中科院分区：
文献类型：
--
作者：
Gaggioli, Carlo Alberto;Belpassi, Leonardo;Belanzoni, Paola
自旋禁阻化学反应涉及从反应物到产物的总电子自旋状态的变化。机理研究具有挑战性，因为这种反应不会发生在单个非绝热势能表面（PES）上，而是发生在两个（或多个）自旋非绝热势能表面上。一种可能的方法是计算非绝热 PES 之间的所谓“最小能量交叉点”(MECP)，但它不是静止点。包含自旋态之间的自旋轨道耦合（SOC 方法）允许反应在单个绝热 PES 上发生，其中可以计算过渡态（TS SOC）以及活化自由能。这篇概念文章总结了之前发表的应用，其中首次包含了在密度泛函理论 (DFT) 框架内使用自旋轨道 ZORA 哈密顿量的 SOC 效应，并解释了金化学中自旋禁阻反应的机制。考虑到我们最近对金（I）-氢化物配合物中分子氧加成的计算以及原型自旋禁阻 N2O 和 N2Se 解离反应的新计算，对 MECP 和 TS SOC 方法的优点以及结果的准确性进行了比较。
A spin-forbidden chemical reaction involves a change in the total electronic spin state from reactants to products. The mechanistic study is challenging because such a reaction does not occur on a single diabatic potential energy surface (PES), but rather on two (or multiple) spin diabatic PESs. One possible approach is to calculate the so-called "minimum energy crossing point" (MECP) between the diabatic PESs, which however is not a stationary point. Inclusion of spin-orbit coupling between spin states (SOC approach) allows the reaction to occur on a single adiabatic PES, in which a transition state (TS SOC) as well as activation free energy can be calculated. This Concept article summarizes a previously published application in which, for the first time, the SOC effects, using spin-orbit ZORA Hamiltonian within density functional theory (DFT) framework, are included and account for the mechanism of a spin-forbidden reaction in gold chemistry. The merits of the MECP and TS SOC approaches and the accuracy of the results are compared, considering both our recent calculations on molecular oxygen addition to gold(I)-hydride complexes and new calculations for the prototype spin-forbidden N2O and N2Se dissociation reactions.