Infrared spectroscopic analysis of cooperative proton transfer induced by synergistic stretching vibrations in water clusters

Our research has discovered a significant correlation between coordinated proton transfer and O-H stretching vibrations in water clusters. Through the application of infrared spectroscopic techniques, we explored the dynamics of hydrogen bond (H-bond) transfer within the cyclic and prismatic molecular structures of water, with a particular emphasis on nuclear vibrational characteristics. The cooperative hydrogen exchange is most intimately associated with symmetric stretching vibrations. Protons within water clusters travel through the hydrogen bonding network, which is driven by nuclear motions. In the transition state, the O-H bonds break, and protons form new connections with adjacent oxygen atoms without relying on covalent bond energy. These phenomena exhibit strong correlations among neighboring bonds, which are determined by the structure of the hydrogen bond network. We investigated how the spatial configuration of water molecules and the properties of hydrogen bonds affect both the direction and efficiency of proton transfer. Our results suggest that vibrational energy levels contribute to regulating these dynamics. They can either facilitate or impede proton transfer depending on the mode and intensity of vibrations. These findings provide crucial insights into the proton transfer mechanisms in water clusters and emphasize the value of infrared spectroscopy in studying such processes. Ultimately, they enhance our understanding of proton dynamics in aqueous systems and more complex biological processes.