The free OD at the air/D2O interface is structurally and dynamically heterogeneous.
The free OD at the air/D2O interface is structurally and dynamically heterogeneous.
复制标题
空中/D2O 接口处的自由 OD 在结构和动态上是异构的。
DOI：
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发表时间：
2013
影响因子：
3.3
通讯作者：
R. Campen
中科院分区：
文献类型：
--
作者：
Yujin Tong;A. V. Verde;A. V. Verde;R. Campen
空气/水界面在环境和技术中普遍存在，并且更普遍地是疏水溶剂化的有用模型。先前的实验和计算研究已经强调，这种扩展的疏水表面的分子水平标记是断裂的氢键，因此，不是氢键供体的OH基团：游离OH。因此，了解这些自由OH的时间平均结构和结构动力学在发展定量的、分子水平的疏水溶剂化理解中起着至关重要的作用。在这里，我们表明，通过结合偏振相关的振动和频（VSF）光谱和分子动力学模拟，在空气/D2 O界面的D2 O的自由OD的结构和动态异质性：寿命较长的自由OD组往往指向更接近表面法线，有一个较窄的取向分布，并更接近气相。这种结构的异质性的知识，应有助于连接现有的描述疏水溶剂化集中在散装氢键网络或局部密度波动的终止。此外，本研究的结果澄清，该计划，以增加信号噪声比VSF测量延迟可见光脉冲相对于红外线应仅与独立的约束系统的结构动力学。
Air/water interfaces are both ubiquitous in the environment and technology and a useful model for hydrophobic solvation more generally. Previous experimental and computational studies have highlighted that molecular level markers of such an extended hydrophobic surface are broken hydrogen bonds and, as a result, OH groups that are not hydrogen bond donors: free OH. Understanding both the time-averaged structure and structural dynamics of these free OH thus plays a critical role in developing a quantitative, molecular level understanding of hydrophobic solvation. Here we show, by combining polarization-dependent vibrational sum frequency (VSF) spectroscopy and molecular dynamics simulation, that the free OD of D2O at the air/D2O interface is structurally and dynamically heterogeneous: that longer lived free OD groups tend to point closer to the surface normal, have a narrower orientational distribution, and are closer to the vapor phase. Knowledge of this structural heterogeneity should help link existing descriptions of hydrophobic solvation that focus either on the termination of the bulk hydrogen bond network or local density fluctuations. In addition the results of this study clarify that schemes to increase signal-to-noise ratios in VSF measurements by delaying the visible pulse relative to the infrared should be used only with independent constraints on the system's structural dynamics.
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DOI：
10.1021/jz101461d
发表时间：
2011
期刊：
The journal of physical chemistry letters
影响因子：
--
作者：
Jiang W;Hardy DJ;Phillips JC;Mackerell AD Jr;Schulten K;Roux B
通讯作者：
Roux B
DOI：
10.1021/jp909219k
发表时间：
2010-02-11
期刊：
The journal of physical chemistry. B
影响因子：
--
作者：
Willard AP;Chandler D
通讯作者：
Chandler D
DOI：
10.1021/jp909048f
发表时间：
2010-02-04
期刊：
The journal of physical chemistry. B
影响因子：
--
作者：
Patel AJ;Varilly P;Chandler D
通讯作者：
Chandler D
影响因子：
3.3
作者：
Patel, Amish J.;Varilly, Patrick;Jamadagni, Sumanth N.;Hagan, Michael F.;Chandler, David;Garde, Shekhar
通讯作者：
Garde, Shekhar