Raman Spectrum of Heavy Water

Abstract

The Raman spectra of two samples of heavy water, one 18 percent and the other 80 percent, were excited by the 2536 line of mercury. The 18 percent heavy water gave the usual band ($\ensuremath{\Delta}\ensuremath{\nu}=3445$) and a new band ($\ensuremath{\Delta}\ensuremath{\nu}=2623$). The new band is probably due to the molecule ${\mathrm{H}}^{2}$O${\mathrm{H}}^{1}$. With 80 percent heavy water the new band was much stronger than the 3445 band but was shifted slightly towards shorter wave-lengths. With the 80 percent sample the 3445 band was shifted slightly toward the red with respect to ordinary water. From the amount of shift it is concluded that molecules containing only one atom of heavy hydrogen give two bands, $\ensuremath{\Delta}\ensuremath{\nu}=2623$ and $\ensuremath{\Delta}\ensuremath{\nu}=3500$, while the molecules made of two heavy hydrogen atoms give a single band $\ensuremath{\Delta}\ensuremath{\nu}=2517$. These bands have been photographed as lines in the case of heavy water vapor.