Description:
<jats:p>Infrared and Raman spectra are presented for solid CH3ZnBH4 and CH3ZnBD4, and these results indicate that the solid is best viewed as being composed of coupled CH3Zn+··· BH4− ions. Least squares valence force constant calculations based on an assumed D2d symmetry for the BH4− ion reproduce the observed frequencies quite well but unfortunately shed no light on the extent of distortion because of correlation between the distortion parameters and the force constants. Reasonable force constants are obtained for distortions of ± 10° from the tetrahedral angle, and these are only slightly different from those of ``free'' BH4− in NH3. Comparison of the BH4− ions in CH3ZnBH4 and BeB2H8 suggests that the BH4− ion is more strongly coupled to the cation in the latter compound.</jats:p>