The quest to uncover the nature of benzonitrile anion
The quest to uncover the nature of benzonitrile anion
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DOI：
10.1039/c9cp06484b
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发表时间：
2020-03-07
影响因子：
3.3
通讯作者：
Krylov, Anna I.
中科院分区：
文献类型：
--
作者：
Gulania, Sahil;Jagau, Thomas-C.;Krylov, Anna I.
用高能级电子结构方法研究了苯甲腈的阴离子状态。用运动方程耦合团簇理论对电子附着态的计算证实了从光剥离实验中得出的结论，即阴离子的基态是价B-2(1)态，而偶极束缚态绝热地类似于上面的0.1 eV。包含三重激发和零点振动能对于恢复相对态的正确有序性是很重要的。计算的Franck-Condon因子和光脱离截面进一步证实了所观察到的光脱离谱来源于价态阴离子。价阴离子在其平衡几何构型上是电子束缚的，但在中性的平衡几何构型下它是亚稳的。偶极束缚态是唯一处于中性平衡几何构型的束缚阴离子态，可以作为俘获电子的关口态。因此，新出现的机制图需要通过偶极束缚态捕获电子，然后是非绝热弛豫形成价阴离子。
Anionic states of benzonitrile are investigated by high-level electronic structure methods. The calculations using equation-of-motion coupled-cluster theory for electron-attached states confirm earlier conclusions drawn from the photodetachment experiments wherein the ground state of the anion is the valence B-2(1) state, while the dipole bound state lies adiabatically similar to 0.1 eV above. Inclusion of triple excitations and zero-point vibrational energies is important for recovering relative state correct ordering. The computed Franck-Condon factors and photodetachment cross-sections further confirm that the observed photodetachment spectrum originates from the valence anion. The valence anion is electronically bound at its equilibrium geometry, but it is metastable at the equilibrium geometry of the neutral. The dipole-bound state, which is the only bound anionic state at the neutral equilibrium geometry, may serve as a gateway state for capturing the electron. Thus, the emerging mechanistic picture entails electron capture via a dipole bound state, followed by non-adiabatic relaxation forming valence anions.