Knowledge Bank

Raman spectra of a single crystal and Raman, infrared and far ir spectra of crystalline undeuterated and partly deuterated powder were recorded in the temperature range $300-17\circ K$. Spectroscopic evidence indicated a linear and symmetric $UO2$ group with $\nu S$ at the rather low value of 783 $cm-1$ (R) and $\nu as$ at 850 $cm-1$ (ir). Hydrogen bonding appeared to be a dominant feature in this compound as all observed stretching vibrations involving H or D were observed at significantly lower values than in the gas phase. Complete correlation field splitting was observed especially well in the case of the $\nu S$ (N-O) vibration at 919 $(B19),921(Ag),923(B29) and cm-1(B39)$ in agreement with the predictions for a $D2h$ factor group.