Identifying 2- and 3-coordinated H2O in protonated ion water clusters by vibrational pre-dissociation spectroscopy and ab initio calculations
Identifying 2- and 3-coordinated H2O in protonated ion water clusters by vibrational pre-dissociation spectroscopy and ab initio calculations
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DOI：
10.1063/1.475294
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发表时间：
1997-12
影响因子：
4.4
通讯作者：
Yi-Siang Wang;Jyh‐Chiang Jiang;Chia‐Liang Cheng;S. Lin;Yungja Lee;H. Chang
中科院分区：
文献类型：
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作者：
Yi-Siang Wang;Jyh‐Chiang Jiang;Chia‐Liang Cheng;S. Lin;Yungja Lee;H. Chang
通过振动预解离光谱研究了水在质子化分子离子上的聚集。不同簇尺寸的系统测量揭示了 NH4+(H2O)n、CH3NH3+(H2O)n 和 H3O+(H2O)n 之间的 OH 拉伸光谱非常相似。特别是在 n⩾6 时，在 3690 cm−1 处出现自由 OH 拉伸的尖锐特征，与冰和水面上发现的特征相同。该特征与其他游离 OH 吸收不同，通常在 3715 cm−1 处的中小型 (H2O)n 团簇中观察到。这些结果与从头计算相结合，为质子化离子水簇中存在 2 配位和 3 配位 H2O 提供了令人信服的证据。
Clustering of water on protonated molecular ions has been investigated by vibrational predissociation spectroscopy. Systematic measurements at different cluster sizes reveal a close resemblance of the OH stretch spectra between NH4+(H2O)n, CH3NH3+(H2O)n, and H3O+(H2O)n. Particularly at n⩾6, a sharp feature, identical to that found on ice and water surfaces, emerges at 3690 cm−1 for free-OH stretching. The feature is distinguished from the other free-OH absorption, commonly observed for small- and medium-sized (H2O)n clusters at 3715 cm−1. The results, in conjunction with ab initio calculations, provide compelling evidence for 2- and 3-coordinated H2O in the protonated ion–water clusters.