Knowledge Bank

We have observed two sets of vibrational satellites for each of $LiBH4$, $NaDH4$, $NaBD4$, and $KBH4$ and have assigned them to the non-degenerate alkali metal-boron stretching state and the degenerate $BH4$ bending (or internal rotation) state. The observed spectral patterns were metal found quite different for different molecular species. The most conspicuous anomaly the $DJK$ constant of $NaBH4$, which was opposite in sign for the two vibrational states, and was accounted for by accidental degenercy of the two states strongly coupled by a Coriolis interaction.