Spectroscopic properties of rare earth borohydrides: Er(BH/sub 4/)/sub 3/-3THF in pure and mixed crystals. Technical report No. 7, 1 Jan--1 Jun 1975

Technical Report · Thu Jun 12 04:00:00 EDT 1975

OSTI ID:7349422

Bernstein, E R; Chen, K M

The optical spectra of Er(BH/sub 4/)/sub 3/-3THF neat crystals and La, Gd, Y(BH/sub 4/)/sub 3/-3THF mixed crystals are reported and analyzed. Lanthanum borohydride is found to have a different room temperature crystal structure (triclinic) from Er, Gd, Y(BH/sub 4/)/sub 3/-3THF(Pbcn). 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 Er(BH/sub 4/)/sub 3/-3THF in Er, Y, Gd(BH/sub 4/)/sub 3/-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 U(BH/sub 4/)/sub 4/. Er(BH/sub 4/)/sub 3/-3THF/La(BH/sub 4/)/sub 3/-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. (GRA)

• Research Organization: Princeton Univ., NJ (USA). Dept. of Chemistry
• OSTI ID: 7349422
• Report Number(s): AD-A-010856
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
BOROHYDRIDES
BORON COMPOUNDS
CRYSTAL STRUCTURE
ERBIUM COMPOUNDS
GADOLINIUM COMPOUNDS
HYDROGEN COMPOUNDS
INFRARED SPECTRA
LANTHANUM COMPOUNDS
PHASE TRANSFORMATIONS
RAMAN SPECTRA
RARE EARTH COMPOUNDS
SPECTRA
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS