Surface enhanced Raman scattering of interfacial DOD, HOD, and OD−

The surface enhanced Raman scattering (SERS) of the O-D stretching modes of interfacial OD− ions, DOD molecules in D2O, and HOD molecules in an equal mixture of D2O and H2O has been observed. The SERS intensity-potential behavior of interfacial water depends upon the hydration energy of the metal cations. When D2O or an equal mixture of D2O and H2O is used as the solvent, the SERS line shape of interfacial water is different. These differences can be explained in terms of the orientation and environment of interfacial DOD and HOD molecules.