Question

The major product formed from the reaction between B$_2$H$_6$ and two equivalents of NH$_3$ at 300 $^\circ$C is _ _ _.

• A. BH$_3\cdot$NH$_3$
• B. [NH$_4$]$^+$ [BH$_4$]$^-$
• C. [(H$_3$N)$_2$BH]$^{2+}$ 2[BH$_4$]$^-$
• D. (HBNH)$_3$

Hint:

At high temperature, ammonia borane loses hydrogen and forms borazine (HBNH)$_3$, an aromatic inorganic compound

Answer 1

The Correct Option is D

Step 1: First step.
Diborane and ammonia first give the simple adduct ammonia borane, BH$_3\cdot$NH$_3$.

Step 2: Effect of heating.
At about 300 degrees Celsius this adduct loses hydrogen gas.

Step 3: Ring formation.
Loss of hydrogen builds the six membered ring borazine, (HBNH)$_3$, often called inorganic benzene.

Step 4: Answer.
\[ \boxed{(HBNH)_3} \]