...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Microhydration of Contact Ion Pairs in M~(2+)OH~?(H_2O)_(n=1?5) (M = Mg, Ca) Clusters: Spectral Manifestations of a Mobile Proton Defect in the First Hydration Shell
【24h】

Microhydration of Contact Ion Pairs in M~(2+)OH~?(H_2O)_(n=1?5) (M = Mg, Ca) Clusters: Spectral Manifestations of a Mobile Proton Defect in the First Hydration Shell

机译：M〜（2+）OH〜？（H_2O）_（n = 1？5）（M = Mg，Ca）团簇中接触离子对的微水合：第一水合壳中移动质子缺陷的光谱表现

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Vibrational predissociation spectra of D_2-“tagged” Mg~(2+)OH~?(H_2O)_(n=1?6) and Ca~(2+)OH~?(H_2O)_(n=1?5) clusters are reported to explore how the M~(2+)OH~? contact ion pairs respond to stepwise formation of the first hydration shell. In both cases, the hydroxide stretching frequency is found to red-shift strongly starting with addition of the third water molecule, quickly becoming indistinguishable from nonbonded OH groups associated with solvent water molecules by n = 5. A remarkably broad feature centered around 3200 cm~(?1) and spanning up to ~1000 cm~(?1) appears for the n ≥ 4 clusters that we assign to a single-donor ionic hydrogen bond between a proximal first solvent shell water molecule and the embedded hydroxide ion. The extreme broadening is rationalized with a theoretical model that evaluates the range of local OH stretching frequencies predicted for the heavy particle configurations available in the zero-point vibrational wave function describing the low-frequency modes. The implication of this treatment is that extreme broadening in the vibrational spectrum need not arise from thermal fluctuations in the ion ensemble, but can rather reflect combination bands based on the OH stretching fundamental that involve many quanta of low-frequency modes whose displacements strongly modulate the OH stretching frequency.
机译：D_2-“标记的” Mg〜（2+）OH〜？（H_2O）_（n = 1？6）和Ca〜（2+）OH〜？（H_2O）_（n = 1？5）的振动预离解谱报道了聚类以探索M〜（2+）OH〜？接触离子对响应于第一水合壳的逐步形成。在这两种情况下，发现从添加第三个水分子开始，氢氧化物的拉伸频率就会发生强烈的红移，并迅速与与溶剂水分子相关的非键合OH基区分开n =5。一个非常宽的特征集中在3200 cm〜 （？1）出现并跨越约1000 cm〜（？1），这是因为我们将n≥4个簇分配给了近端第一个溶剂壳水分子和嵌入的氢氧根离子之间的单供体离子氢键。使用理论模型合理化极端扩展，该模型评估了在描述低频模式的零点振动波函数中可用的重粒子构型预测的局部OH拉伸频率范围。这种处理的含义是，振动谱的极端展宽不一定来自离子系综的热涨落，而可以反映基于OH拉伸基础的组合带，该组合带涉及许多低频模式的量子，其位移强烈地调节了OH拉伸频率。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号