Formula of Inorganic Benzene
Inorganic benzene is also known as borazine which is an inorganic and a cyclic compound. There are three BH units and three NH units alternate. The chemical formula of inorganic benzene is:
| (BH)3(NH)3 |
Inorganic Benzene Structure
Why is borazine called “inorganic benzene”?
Borazine is called “inorganic benzene” because the compound is isoelectronic and isostructural with benzene. The other similarities are it is a colourless liquid with aromatic smell. Borazine is said to be aromatic because the number of pi electrons obeys 4n+2 rule and the B-N bond lengths are all equal.
Preparation of Inorganic Benzene
There are three different ways to prepare inorganic benzene and they are:
- Stock and Pohlands method:\(3B_{2}H_{6}+6NH_{3}\rightarrow 3[B_{2}H_{6}.NH_{3}]\rightarrow 2B_{3}N_{3}H_{6}+12H_{2}\)The yield obtained by this method is low because there is a simultaneous formation of solid polymeric by-products.
- Heating BCl3 with NH4Cl:
\(3NH_{4}Cl+3BCl_{3}\rightarrow[C_{6}H_{5}cl,Fe]{140^{\circ} C}Cl_{3}B_{3}N_{3}H_{3}+9HCl\) \(3Cl_{3}B_{3}N_{3}H_{3}+6LiBH_{4}\overset{[H]}{\rightarrow}2B_{3}N_{3}H_{6}+6LiCl+3B_{2}H_{6}\) - By heating mixture of LiBH4 and NH4Cl:\(3NH_{4}Cl+3LiBH_{4}\overset{230^{\circ}C}{\rightarrow}B_{3}N_{3}H_{6}+3LiCl+9H_{2}\)This method gives up to 30% Borazine.