Institute of Biochemistry and Biophysics Polish Academy of Sciences, Pawińskiego 5a, 02-106, Warsaw, Poland.
Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
Sci Rep. 2022 Nov 4;12(1):18732. doi: 10.1038/s41598-022-23551-9.
Normal and heavy water are solvents most commonly used to study the isotope effect. The isotope effect of a solvent significantly influences the behavior of a single molecule in a solution, especially when there are interactions between the solvent and the solute. The influence of the isotope effect becomes more significant in DO/HO since the hydrogen bond in HO is slightly weaker than its counterpart (deuterium bond) in DO. Herein, we characterize the isotope effect in a mixture of normal and heavy water on the solvation of a HOD molecule. We show that the HOD molecule affects the proximal solvent molecules, and these disturbances are much more significant in heavy water than in normal water. Moreover, in DO, we observe the formation of low-density structures indicative of an ordering of the solvent around the HOD molecule. The qualitative differences between HOD interaction with DO and HO were consistently confirmed with Raman spectroscopy and NMR diffusometry.
正常水和重水是最常用于研究同位素效应的溶剂。溶剂的同位素效应对单个分子在溶液中的行为有显著影响，特别是当溶剂和溶质之间存在相互作用时。在 DO/HO 中，由于 HO 中的氢键比 DO 中的氢键略弱，因此同位素效应的影响更加显著。在此，我们研究了 HOD 分子在正常水和重水混合物中的溶剂化作用中的同位素效应。结果表明，HOD 分子会影响近邻溶剂分子，而在重水中，这种干扰比在普通水中更为显著。此外，在 DO 中，我们观察到形成了低密度结构，表明溶剂在 HOD 分子周围有序排列。用拉曼光谱和 NMR 扩散测量法一致证实了 HOD 与 DO 和 HO 的相互作用存在定性差异。
