Dynamics of π*-resonances in anionic clusters of para-toluquinone.
Dynamics of π*-resonances in anionic clusters of para-toluquinone.
复制标题
对甲苯醌阴离子簇中 π* 共振的动力学。
DOI：
10.1039/c7cp03628k
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
J. Verlet
中科院分区：
文献类型：
--
作者：
J. Bull;J. Verlet
频率分辨光电子能谱应用于质量选择簇阴离子是一种有见地的方法来解释π*-共振与微溶剂化的动力学。在这里，该技术被证明与单体，二聚体和三聚体自由基阴离子的对甲苯醌（PTQ）超过一个101 eV的激发窗口以上的脱离阈值。的pTQ-光谱显示类似的共振和动力学对苯醌，原型电泳。二聚体（pTQ）2-具有π-堆叠几何结构，并显示出光解离和快速自分离之间的竞争。三聚体，（pTQ）3-，也有一个π堆叠的集群几何形状，并显示振动自脱离从非价态高达0.7 eV以上的阈值，竞争解离。在较高的光激发能下，（pTQ）3-表现出类似单体的动力学，光激发能蓝移的集群内聚能。总的来说，这项研究强调了π* 共振的非绝热动力学的多样性，以及通过一个和两个单体的集群化发生的深刻变化。
Frequency-resolved photoelectron spectroscopy applied to mass-selected cluster anions is an insightful approach to characterise the dynamics of π*-resonances with microsolvation. Here, the technique is demonstrated with monomer, dimer and trimer radical anions of para-toluquinone (pTQ) over a ∼1 eV excitation window above the detachment threshold. The pTQ- spectra show similar resonances and dynamics to para-benzoquinone, a prototype electrophore. The dimer, (pTQ)2-, has a π-stacked geometry and shows a competition between photodissociation and prompt autodetachment. The trimer, (pTQ)3-, also has a π-stacked cluster geometry and shows vibrational autodetachment from a non-valence state up to ∼0.7 eV above-threshold, outcompeting dissociation. At higher photoexcitation energies, (pTQ)3- shows monomer-like dynamics, blue-shifted in photoexcitation energy by the cluster cohesion energy. Overall, the study highlights the variety of non-adiabatic dynamics available to π*-resonances and the profound changes that occur through clusterization with one and two monomers.