Ice nanoclusters at hydrophobic metal surfaces
Ice nanoclusters at hydrophobic metal surfaces
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DOI：
10.1038/nmat1940
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发表时间：
2007-08-01
期刊：
影响因子：
41.2
通讯作者：
Morgenstern, Karina
中科院分区：
文献类型：
--
作者：
Michaelides, Angelos;Morgenstern, Karina
对支撑水团簇结构的研究提供了一种手段，可以对非均质冰成核的初始阶段进行严格的分子尺度描述：这一过程对大气化学、天体物理和生物学等多个领域都很重要。在这里，我们通过低温扫描隧道显微镜实验和第一性原理电子结构计算相结合的方法，观察和表征了金属支撑的水六聚体和一类水合纳米团簇--七聚体、八聚体和九聚体。除了实现对循环水六角体-所谓的最小一块冰-的前所未有的分辨率外，我们还发现并解释了水分子同时与底物结合的能力和接受氢键的能力之间的一种迄今未知的竞争。这项竞赛也使先前对其他底物上的水团簇的结构预测合理化。
Studies of the structure of supported water clusters provide a means for obtaining a rigorous molecular-scale description of the initial stages of heterogeneous ice nucleation: a process of importance to fields as diverse as atmospheric chemistry, astrophysics and biology. Here, we report the observation and characterization of metal-supported water hexamers and a family of hydrated nanoclusters-heptamers, octamers and nonamers-through a combination of low-temperature scanning tunnelling microscopy experiments and first-principles electronic-structure calculations. Aside from achieving unprecedented resolution of the cyclic water hexamer-the so-called smallest piece of ice-we identify and explain a hitherto unknown competition between the ability of water molecules to simultaneously bond to a substrate and to accept hydrogen bonds. This competition also rationalizes previous structure predictions for water clusters on other substrates.