Kinetics of Hydrogen-to-Deuterium Exchange Compared to Deuterium-to-Hydrogen Exchange in Hydrogen Bonds within a Model Peroxo Complex

Hydrogen and deuterium atom exchange kinetics in covalent chemical bonds help establish structure, and function of individual molecules. On the other hand, hydrogen bonding is vital to collective properties of many molecules in assemblage. Herein we report that D2O to H2O exchange is 11-fold faster than H2O to D2O, and D2O to HOD is 4-fold faster than H2O to HOD exchange in a hydrogen bonded solvent-Complex system. In this regard, we have utilized a polynuclear peroxo complex where each peroxo oxygen was linked to a hydrogen bond with the solvent molecule (H2O or D2O or HOD). The kinetics studies involving the exchange of peroxo-D2O/H2O with peroxo-H2O/D2O/HOD were pursued using surface enhanced resonance Raman scattering of the peroxo complex on Au nanoparticles. The results indicate the importance of chemical kinetics involving hydrogen bonding of molecules in aqueous medium.