Terahertz Pulsed Spectroscopy as a New Tool for Measuring the Structuring Effect of Solutes on Water
Terahertz Pulsed Spectroscopy as a New Tool for Measuring the Structuring Effect of Solutes on Water
复制标题
太赫兹脉冲光谱作为测量溶质对水的结构效应的新工具
作者：
N. Kaun;J. Baena;D. Newnham;B. Lendl
在中红外（MIR）和太赫兹（THz）光谱区记录了“混沌型”（结构制造者）和“宇宙型”（结构破坏者）水溶液的吸收光谱。在记录的太赫兹光谱中发现两组溶质对水的吸收光谱有不同的影响。所有研究的乱向溶液都记录了在所研究的太赫兹光谱区域（分别为0.04-2太赫兹，1.3-66 cm−1）的浓度依赖的吸收增加，而对于含宇宙色线的溶液则相反。在离子溶质的情况下，测量到对更高频率的吸收进一步增加。正如预期的那样，在MIR光谱区域也可以区分混沌质和宇宙质。根据溶质的结构形成效应，水的OH拉伸振动（约3400 cm−1）略有变化。对于宇宙色偏的溶液，观察到红移，而对于含有混沌色偏的溶液，观察到蓝移。与MIR光谱区相比，太赫兹光谱区可以更有效地研究溶质的结构影响效应，它提供了邻近水分子之间相互作用的信息。
Absorption spectra of aqueous solution of “chaotropes” (structure maker) and “kosmotropes” (structure breaker) have been recorded in the mid-infrared (MIR) and terahertz (THz) spectral region. A different impact of the two groups of solutes on the absorption spectrum of water was found in the recorded THz spectra. A concentration-dependent increased absorption across the investigated THz spectral region (0.04–2 THz, 1.3–66 cm−1, respectively) has been recorded for all studied chaotropic solutions, whereas the opposite has been obtained for kosmotrope containing solutions. In the case of ionic solutes a further increase in absorption towards higher frequencies was measured. The distinction between chaotrope and kosmotrope solutes was, as expected, also possible in the MIR spectral region. Depending on the structure-forming effect of the solute the OH stretch vibration of the water (around 3400 cm−1) was slightly shifted. A red shift has been observed for solution of kosmotropes, whereas a blue shift was observed in the case of solutions containing chaotropes. Compared to the MIR spectral region the structure influencing effect of solutes can be more efficiently studied in the THz spectral region, which provides information from interactions between neighboring water molecules.
影响因子：
15
作者：
Hribar, B;Southall, NT;Dill, KA
通讯作者：
Dill, KA