Infrared photodissociation spectroscopic studies of ScO(H2O)(n=1-3)Ar+ cluster cations: solvation induced reaction of ScO+ and water
Infrared photodissociation spectroscopic studies of ScO(H2O)(n=1-3)Ar+ cluster cations: solvation induced reaction of ScO+ and water
复制标题
ScO(H2O)n=1-3Ar簇阳离子的红外光解光谱研究：ScO和水的溶剂化诱导反应
DOI：
10.1039/c9cp02171j
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发表时间：
2019
影响因子：
3.3
通讯作者：
Wang Guanjun
中科院分区：
文献类型：
--
作者：
Chen Yinjuan;Jin Jiaye;Xin Ke;Yu Wenjie;Xing Xiaopeng;Wang Xuefeng;Wang Guanjun
利用红外光解离光谱研究了激光蒸发与超声分子束耦合制备的ScO（H_2O）_1 -3Ar ~+离子的O-H伸缩区。阳离子结构的特征在于通过比较实验观察到的频率与模拟的振动光谱。我们发现，化学计量的ScO（H2O）Ar+本质上是水合氧化物阳离子，表示为H2O-ScOAr+水合物，而不是Sc（OH）2Ar+二氢氧化物，尽管前者的能量比后者高29.5 kcalmol-1。有趣的是，当更多的水分子被引入到配合物中时，我们发现化学计量的ScO（H2O）2-3Ar+包围了Sc（OH）2+的核心亚基。理论计算表明，氢转移能垒在水合络合物异构化为氢氧化物的过程中起着关键作用。当一个以上的水分子参与复合物时，氢转移通过六元环状过渡态变得几乎无势垒，导致能垒从21.8 kcal mol−1降低到4.2 kcal mol−1。总的来说，我们得出的结论是，溶剂分子，如水，可以降低能量势垒，从而诱导羟基物种的形成在水解过程中。
We investigate the gaseous ScO(H2O)1–3Ar+ cations prepared by laser vaporization coupled with supersonic molecular beam using infrared photodissociation spectroscopy in the O–H stretching region. The cation structures are characterized by comparing the experimentally observed frequencies with the simulated vibration spectra. We reveal that stoichiometric ScO(H2O)Ar+ is intrinsically the hydrated oxide cation expressed as H2O–ScOAr+ hydrate rather than Sc(OH)2Ar+ dihydroxide, although the former is higher in energy by 29.5 kcal mol−1 than the latter. Interestingly, when more water molecules are introduced to the complex, we find that the stoichiometric ScO(H2O)2–3Ar+ embraces the core subunit of Sc(OH)2+. Theoretical calculations suggest that the energy barrier of hydrogen transfer plays a critical role in the isomerization from hydrated complex to dihydroxide. When more than one water molecule is involved in the complex, the hydrogen transfer becomes nearly barrierless through a six-member cyclic transition state, leading to the reduction in the energy barrier from 21.8 kcal mol−1 to 4.2 kcal mol−1. Altogether, we conclude that the solvent molecules such as water can decrease the energy barrier and thus induce the formation of hydroxy species in the hydrolysis process.