Metal borohydride( iv) Diborane reacts with ammonia to give borazine at 450 K.
B2H6 + 6NH3
→ 3B3N3H6 + 12H2
Borazine has a cyclic structure similar to benzene and thus is called inorganic benzene
The other elements of this group form only a few stable hydrides. The thermal stability decreases as we move down the group.
AlH3 is a colourless solid polymerized via Al- H- Al bridging units. These hydrides are weak Lewis acids and readily form adducts with strong Lewis base( B:) to give compounds of the type MH3( M = Al or Ga). They also form complex-tetrahydrido anions, [ MH4 ]-. The most important tetrahydrido compound is Li [ AlH4 ]
ether 4LiH + AlCl3 ――― → LiAlH4 + 3LiCl
OXIDES & HYDROXIDES
• M2O3 & M( OH) 3
HALIDES: Structure of boron trihalides