Spectroscopic Properties of Rare Earth Borohydrides: Er(BH4)3-3THF In Pure and Mixed Crystals.
Technical rept. no. 7, 1 Jan-1 Jun 75,
PRINCETON UNIV N J DEPT OF CHEMISTRY
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The optical spectra of ErBH43-3THF neat crystals and La, Gd, YBH43-3THF mixed crystals are reported and analyzed. Lanthanum borohydride is found to have a different room temperature crystal structure triclinic from Er, Gd, YBH43-3THFPbcn. At low temperature the Pbcn crystals undergo a phase transition to a structure with two crystallographically inequivalent sites in a unit cell. The optical spectra of ErBH43-3THF in Er, Y, GdBH43-3THF crystals clearly evidence these two sites. Large vibronic intensity is observed at 1.6K and 77K and nine molecular vibrations are assigned. These modes are quite similar to those found for UBH44. ErBH43-3THFLaBH43-3THF spectra are very different no vibronic transitions are observed but many often upwards of fifty for a given manifold weak sharp satellite lines are found associated with pure electronic transitions. These data are discussed in terms of structural differences and comments on bonding and covalent character in lanthanide borohydrides are made.
- Atomic and Molecular Physics and Spectroscopy
- Solid State Physics