Correlations between the Structures and Spectra of Protonated Water Clusters
Correlations between the Structures and Spectra of Protonated Water Clusters
复制标题
质子化水团簇结构与光谱之间的相关性
DOI：
10.1021/acs.jpca.3c07338
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
McCoy, Anne B.
中科院分区：
文献类型：
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作者：
Finney, Jacob M.;McCoy, Anne B.
Badger的氢氧根拉伸频率和强度与氢氧根键长度之间的类似规则的相关性被用于开发用于研究纯和质子化水簇的光谱映射程序。这种方法利用了OH键的振动平均长度，这是由Yu和Bowman开发的通用势进行扩散蒙特卡罗模拟得到的。使用这种方法获得的光谱与先前报道的H+(H2O)nclusters （n= 3、4和5）及其perdeuterated类似物的光谱非常吻合。通过这种光谱映射方法获得的光谱分析支持了先前的工作，即将H+(H2O)6的光谱分配给艾根和赞德尔类结构的混合物。对计算光谱的分析还表明，在H+(H2O)6的本征结构中，一个涉及氢氧根核心氢氧键的氢氧键拉伸振动的跃迁频率从1917 cm-1重新分配到大约2100 cm-1。对于D+(D2O)6，将测量光谱与光谱映射方法得到的光谱进行比较表明，测量光谱的载流子是D+(D2O)6的一种或多种同分异构体，它们含有一个四元环和两个侧水分子。虽然有几种候选结构，但两侧的两个水分子最有可能形成一条链，与水合氢离子核心结合。
Badger’s rule-like correlations between OH stretching frequencies and intensities and the OH bond length are used to develop a spectral mapping procedure for studies of pure and protonated water clusters. This approach utilizes the vibrationally averaged OH bond lengths, which were obtained from diffusion Monte Carlo simulations that were performed using the general potential developed by Yu and Bowman. Good agreement is achieved between the spectra obtained using this approach and previously reported spectra for H+(H2O)nclusters, withn= 3, 4, and 5, as well as their perdeuterated analogues. The analysis of the spectra obtained by this spectral mapping approach supports previous work that assigned the spectrum of H+(H2O)6to a mixture of Eigen and Zundel-like structures. Analysis of the calculated spectra also suggests a reassignment of the frequency of one of the transitions that involves the OH stretching vibration of the OH bonds in the hydronium core in the Eigen-like structure of H+(H2O)6from 1917 cm–1to roughly 2100 cm–1. For D+(D2O)6, comparison of the measured spectrum to those obtained by using the spectral mapping approach suggests that the carrier of the measured spectrum is one or more of the isomers of D+(D2O)6that contain a four-membered ring and two flanking water molecules. While there are several candidate structures, the two flanking water molecules most likely form a chain that is bound to the hydronium core.