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