Inelastic neutron scattering (INS) spectra of NaBH4 and KBH 4 are presented to 1500 cm-1. The phonon spectra contain detail unobserved in IR/Raman studies, including combination bands in the phonon and internal modes of KBH4. The BH4- ion vibrational frequencies observed in the solids at 15 K differ significantly from those observed for BH4- in liquid ammonia solution and normal mode frequency calculations for the isolated ion. The INS spectra and ammonia solution frequencies are compared with isolated anion and k=0 periodic DFT calculations to show that the periodic DFT results correctly predict the solid-state molecular vibrational frequencies.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry