Question

Which of the following statements is correct about borazine?

• A. Borazine is called 'inorganic benzene'
• B. Diborane react with ammonia to give borazine
• C. Like organic benzene, borazine does not give addition product.
• D. Borazine is more reactive than Benzene

Answer 1

Answer: (A), (B), (D)

Borazine is more reactive than Benzene

Borazine is isostructural with benzene. The six B-N bonds have length of 1.436$\stackrel{\circ }{\text{A}}$. The carbon-carbon bond in benzene is shorter length at 1.397$\stackrel{\circ }{\text{A}}$. The boron-nitrogen bond length is between that of the boron-nitrogen single bond with 0.151 nm and the boron-nitrogen double bond which is 0.131 nm. This suggests partial delocalisation of nitrogen lone-pair electrons.
Borazine satisfies the (4n + 2) Huckel's rule and each B and N atom is $s{p}^2$ hybridised. Hence, borazine is a inorganic benzene.

Benzene doesnot undergo addition reaction but borazine undergo addition reaction and it is more reactive than benzene molecule.
When diborane react with ammonia at ratio of 1:2, produce borazine and hydrogen.
$3B_2{H}_6+6N{H}_3\to 6B{H}_3.N{H}_3\to 2B_3{N}_3{H}_6+12H_2\text{Inorganic benzene}$
This reaction takes place at a temperature of $180-{190}^{o}C.$
Thus, the correct statements are (a), (b) and (d).