Infrared Pump鈥揚robe Study of Nanoconfined Water Structure in Reverse Micelle

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• 作者：Jooyong Lee ; Micha艂 Maj ; Kyungwon Kwak ; Minhaeng Cho
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2014
• 出版时间：October 2, 2014
• 年：2014
• 卷：5
• 期：19
• 页码：3404-3407
• 全文大小：260K
• ISSN：1948-7185

文摘

The influence of nanoconfinement on water structure is studied with time- and frequency-resolved vibrational spectroscopy of hydrazoic acid (HN₃) encapsulated in reverse micelle. The azido stretch mode of HN₃ is found to be a promising infrared probe for studying the structure and local hydrogen-bond environment of confined and interfacial water in reverse micelle due to its narrow spectral bandwidth and large transition dipole moment. The results show a clear separation between the core and shell spectral components, making it advantageous over the previously studied infrared probes. The measured vibrational lifetimes appear to be substantially different for the interfacial and bulk-like environments but show no remarkable size dependency, which indicates that water structures around this IR probe are distinctively different in the core and shell regions. The influence of local hydrogen bond network in the first and higher solvation shells on the vibrational dynamics of HN₃ is further discussed.

Keywords:

vibrational spectroscopy; IR pump鈭抪robe spectroscopy; nanoconfined water; reverse micelle; hydrogen bond