Lithium borohydride

Description

Lithium borohydride (LiBH₄) is a tetrahydroborate and known in organic synthesis as a reducing agent for esters. Although less common than the related sodium borohydride, the lithium salt offers some advantages of being highly soluble in ethers and being a stronger reducing agent but still safer to handle than lithium aluminium hydride.

Lithium borohydride may be prepared by the metathesis reaction, which occurs upon ball-milling the more commonly available sodium borohydride, and lithium bromide:

NaBH₄ + LiBr → NaBr + LiBH₄

Lithium borohydride
IUPAC name[hide] Lithium tetrahydridoborate(1–)
Other names[hide] Lithium hydroborate, Lithium tetrahydroborate Borate(1-), tetrahydro-, lithium, lithium boranate
Identifiers
CAS number	16949-15-8
PubChem	4148881
ChemSpider	55732^Y
RTECS number	ED2725000
Jmol-3D images	Image 1
Properties
Molecular formula	LiBH₄
Molar mass	21.784 g/mol
Appearance	White solid
Density	0.666 g/cm^3[1]
Melting point	275 °C^[1]
Boiling point	380 °C (decomp)
Solubility in water	reacts
Solubility in ether	2.5 g/100 mL
Thermochemistry
Std enthalpy of formation Δ_fH^o₂₉₈	-8.759 kJ/g
Specific heat capacity, C	3.792 J/g K
Hazards
Autoignition temperature	> 180 °C
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Strong reducing agent capable of reducing the aldehydes, ketones and esters, etc.