`to` In industries diborane is prepared by the reaction between boran tri fluoride and lithium hydride,
`2BF_3 + 6 LiH overset(450 K)to B_2 H_6 + 6 LiF`
`to` Boron trichloride and hydrogen mixture subjected to silent electric discharge at low pressure to from diborane.
`2BCl_3 + 6H_3 to B_2 H_6 + 6HCl`
`to` Boron trichloride undergo reduction with `LiAlH_4` to form diborane.
`3LiAlH_4 + 4BCl_3 overset("Ether")to 2B_2 H_6 + 3AlCl_3 + 3 LiCl`
Diborane is an electron deficient compound. It has .12. valency electrons for bonding purpose instead of .14. electrons.
In diborane each boron atom undergoes `sp^3` hybridization out of the four hybrid orbitals one is vacant:
Each boron forms two, `sigma` - bonds (2 centred - 2 electron bonds) bonds with two hydrogen atoms by overlapping with their .1s. orbital.
The remaining hybrid orbitals of boran used for the formation of B-H-B bridge bonds.
In the formation of B-H-B bridge, half filled `sp^3` hybrid orbital of one boron atom and vacant `sp^3` hybrid orbital of second boron atom overlap with 1s orbital of H-atom.
These three centred two electron bonds are also called as banana bords. These bonds are present above and below the plane of `BH_2` units.
Diborane contains two coplanar `BH_2` groups. The four hydrogen atoms are called terminal hydrogen atoms and the remaining two hydrogens are called bridge hydrogen atoms.
