Ionisation-induced site switching dynamics in solvated aromatic clusters: phenol–(rare gas) n clusters as prototypical example
Ionisation-induced site switching dynamics in solvated aromatic clusters: phenol–(rare gas) n clusters as prototypical example
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溶剂化芳香族簇中电离诱导的位点切换动力学：苯酚（稀有气体）n簇作为典型例子
DOI：
10.1080/0144235x.2012.656013
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发表时间：
2012
影响因子：
6.1
通讯作者：
O. Dopfer
中科院分区：
文献类型：
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作者：
M. Fujii;O. Dopfer
用电子轰击红外（EI-IR）光解离、纳秒和皮秒时间分辨紫外-紫外-红外光谱（UV-UV-IR）研究了稀有气体PhOH-Rgn（Rg = Ar和Kr，n= 1-3）溶剂化苯酚团簇中电离诱导的π → H位转换反应. PhOH ~+-Rg二聚体的EI-IR光谱表明，在阳离子的基态电子态下，氢键结合的异构体是最稳定的结构，其中Rg原子与PhOH ~+的OH基团形成氢键。Rg配体与芳环相连的π键合结构在EI-IR光谱中也被微弱地检测为不太稳定的结构。的PhOH+-Rg二聚体的红外光谱的急剧变化，当集群阳离子产生的共振增强多光子电离（REMPI）。亚稳态π-束缚结构成为主要的物种，并控制人口。皮秒时间分辨的REMPI-IR光谱清楚地表明了π键合结构通过电离的初始布居，随后的π → H位点切换到H键合位点，以及通过H → π反反应最终形成π/H平衡布居。这种π-Particip-H结构关系对应于Rg原子围绕PhOH+的摆动。π → H开关动力学的影响灵敏地通过添加一个或多个Rg配体的反应机理和速率常数。在较大的PhOH ~+-Rgn团簇中（n≥ 2），初始的π束缚结构通过一个单向单步反应完全转变为H束缚结构，并在皮秒时间尺度上发生单次指数衰减。反应机理中的这一主要变化通过有效的分子间振动能从反应坐标重新分配到可用旁观配体的模式来合理化，这完全猝灭了n ≥ 2时的H → π反反应。讨论了这种π-H位转换的结构、能量学和动力学，沿着讨论了基于波包动力学的量子化学描述。值得注意的是，这些光谱实验PhOH+-Rgn代表的第一个时间分辨的研究分子团簇中的分子间的相互作用反应。
The ionisation-induced π → H site switching reaction in clusters of phenol solvated by rare gas ligands, PhOH–Rgn(Rg = Ar and Kr,n= 1–3), is characterised by electron impact infrared (EI–IR) photodissociation as well as nanosecond and picosecond time-resolved UV–UV–IR spectroscopy. The EI–IR spectra of the PhOH+–Rg dimers demonstrate that the H-bound isomer is the most stable structure in the ground electronic state of the cation, in which the Rg atom forms a hydrogen bond to the OH group of PhOH+. The π-bound structure, in which the Rg ligand is attached to the aromatic ring, is also weakly detected as a less stable structure in the EI–IR spectrum. The IR spectra of the PhOH+–Rg dimers change drastically, when the cluster cations are generated by resonance-enhanced multiphoton ionisation (REMPI). The metastable π-bound structure becomes the major species and dominates the population. The picosecond time-resolved REMPI–IR spectra clearly demonstrate the initial population of the π-bound structure by ionisation, the subsequent π → H site switching to the H-bound site, and the eventual formation of an π/H equilibrium population by the H → π back reaction. Classically, this intermolecular π ↔ H structural rearrangment corresponds to a pendular motion of Rg atom around PhOH+. The π → H switching dynamics is sensitively affected by the addition of one or more Rg ligands with respect to the reaction mechanism and the rate constants. In larger PhOH+–Rgnclusters (n≥ 2), the initially populated π-bound structure is completely converted into the H-bound structure by a one-way single-step reaction with a single exponential decay on the picosecond timescale. This principal change in the reaction mechanism is rationalised by efficient intermolecular vibrational energy redistribution from the reaction coordinate to modes of the available spectator ligand(s), which completely quenches the H → π back reaction forn≥ 2. Structures, energetics and dynamics of this π-H site switching, along with a quantum chemical description based on wavepacket dynamics are discussed. Significantly, these spectroscopic experiments for PhOH+–Rgnrepresent the first time-resolved studies of intermolecular rearrangment reactions in molecular clusters.
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DOI：
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发表时间：
--
期刊：
影响因子：
--
作者：
通讯作者：
--
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DOI：
--
发表时间：
1998
期刊：
影响因子：
--
作者：
R. Olkhov;S. Nizkorodov;O. Dopfer
通讯作者：
O. Dopfer
苯酚-乙醇阳离子的振动光谱
DOI：
10.1021/j100131a014
发表时间：
1993
期刊：
The Journal of Physical Chemistry
影响因子：
--
作者：
E. Cordes;O. Dopfer;T. G. Wright;K. Mueller
通讯作者：
K. Mueller
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影响因子：
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作者：
T. Korter;J. Küpper;D. Pratt
通讯作者：
D. Pratt
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DOI：
10.1063/1.3149780
发表时间：
2009
期刊：
The Journal of chemical physics
影响因子：
--
作者：
I. Kalkman;C. Brand;Thi Bao Chau Vu;W. Meerts;Y. Svartsov;O. Dopfer;X. Tong;K. Müller;S. Grimme;M. Schmitt
通讯作者：
M. Schmitt