2BF3+6NaH→(A)B2H6+6NaF
In this reaction hydride ions replace the fluoride ions. and diborane is formed, which is a Lewis acid due to incomplete octet. It breaks symmetrically with bases like tertiary amines.
B2H6+2Me3N→(B)2(Me3N)+(BH3)−
In this product geometry around Boron will be tetrahedral. And it will have sp3 hybridisation.
