Exploring the dynamic changes in hydrogen bond structure of water and heavy water under external perturbation of DMF.

The Raman spectra of DMF-water/heavy water binary solutions at different volume ratios are measured to investigate the hydrogen bond structure between N, N-dimethylformamide (DMF) and water/heavy water. It was observed that when V below 40 %, DMF reinforces the hydrogen bond among water molecules through the substitution of a small amount of water molecules within the tetrahedral structure. However, a similar enhancement phenomenon is not observed in heavy water. When V is less than 60 %, the hydrogen bonds among DMF and heavy water molecules affect the symmetry of OD covalent bond. Furthermore, as V exceeds 40 %/60 %, the tetrahedral structures of water and heavy water are gradually replaced by DMF·3HO/3DO, DMF·2HO/2DO, and DMF·HO/DO clusters. The transition point of hydrogen bond structure in DMF- aqueous solution moved to V = 15 % under the influence of under the influence of dynamic high pressure caused by pulsed laser beam. This study provides valuable insights into the microstructure of water/heavy water clusters.