Why is inorganic benzene called borazine

Difference Between Borazine and Benzene

The Main difference That lies between borazine and benzene Borazine contains three boron atoms and three nitrogen atoms in the ring structure, while the benzene contains six carbon atoms in the ring structure.

Both borazine and benzene have similar six-membered ring structures, and these two compounds are isoelectronic. That is, both borazine and benzene have the same number of electrons or the same electronic structure. However, they have completely different chemical and physical properties, since the rings of these compounds are made up of different atoms.

CONTENT

1. Overview and key difference
2. What is borazine?
3. What is benzene?
4. Similarities Between Borazine and Benzene
5. Side by side comparison - borazine versus benzene in tabular form
6. Summary

What is borazine?

Borazine is an inorganic compound with the chemical formula B.3H6N3. It is a cyclic compound with a six-membered ring structure. That is, it has three W-H units and three N-H units in an alternating pattern. Hence, we can write its chemical formula as (BH)3) (NH3). This structure is also isoelectronic with the benzene ring. Like benzene, this is also a colorless liquid at room temperature. That's why we sometimes call it "inorganic benzene" ..

Figure 01: Chemical structure of borazine

Furthermore, the molar mass of borazine is 80.50 g / mol. The melting point and boiling points are -58 ° C and 53 ° C, respectively. It also has an aromatic odor. In addition, this is a synthetic compound that we can make from diborane and ammonia in a ratio of 1: 2.

The chemical reaction involved in this process is as follows:

3 B2H6 + 6 NH3 → 2 B3H6N3 + 12 h2

When we add borazine to water, it mainly hydrolyzes to boric acid, ammonia and hydrogen gas. In addition, this connection is thermally very stable due to its low standard enthalpy formation change; -531 kJ / mol. Compared to benzene, borazine is far more reactive. For example, it can react with hydrogen chloride, but benzene cannot.

According to X-ray crystallographic determinations, the bond lengths in the ring structure of borazine are the same. However, it cannot form a perfect hexagon because the alternating pattern of nitrogen and boron results in different bond angles and thus a pronounced molecular symmetry.

What is Benzene?

Benzene is an organic compound with the chemical formula C.6H6. It has a six-membered ring structure with all of the members being carbon atoms. Here each of these carbon atoms is bound to a hydrogen atom. Since this compound only contains carbon and hydrogen atoms, it is a hydrocarbon. This compound occurs naturally primarily as a component of crude oil.

Figure 02: Different representations of benzene

Looking at its properties, the molar mass of benzene is 78.11 g / mol. The melting point and boiling points are 5.53 ° C and 80.1 ° C, respectively. At room temperature, it is also a colorless liquid. It is also an aromatic hydrocarbon. As a result, it has an aromatic smell. In addition, according to X-ray diffraction determinations, all bonds between the six carbon atoms are of similar lengths. Hence it has an intermediate structure. We call it a "hybrid structure" because according to the bond formation there should be alternating single bonds and double bonds between the carbon atoms. Subsequently, the actual benzene structure is the result of several resonance structures of the benzene molecule.

What are the Similarities Between Borazine and Benzene?

  • Both are cyclical structures.
  • Both borazine and benzene also have a six-membered ring.
  • In addition, both have equal bond lengths between the atoms of the ring.
  • In addition, both are colorless liquids at room temperature.
  • Both are also isoelectronic.

What is the difference between borazine and benzene?

Borazine is an inorganic compound with the chemical formula B.3H6N3 while benzene is an organic compound with the chemical formula C.6H6. Therefore, the main difference between borazine and benzene is that the borazine contains three boron atoms and three nitrogen atoms in the ring structure, while benzene contains six carbon atoms in the ring structure. In borazine, the boron and nitrogen atoms alternate. So the borazine molecule is not a perfect hexagon, but benzene only has carbon atoms in the ring. So it can form a perfect hexagon. Hence, we can consider this to be another difference between borazine and benzene.

The main difference between borazine and benzene is that borazine is a synthetic compound, while benzene occurs naturally as the main component in crude oil. We can also tell a difference between borazine and benzene based on their reactivity. In comparison, borazine is more reactive than benzene.

Summary - Borazine vs Benzene

Borazine and benzene are isoelectronic; which means they have the same number of electrons or the same electronic structure. However, they are two different connections. The main difference between borazine and benzene is that the borazine contains three boron atoms and three nitrogen atoms in the ring structure, while the benzene contains six carbon atoms in the ring structure.

Reference:

1. Mn2555 episodes. “BORAZINE structure, preparation and properties.” LinkedIn SlideShare, November 24, 2015. Available here
2. "Benzene". Wikipedia, Wikimedia Foundation, September 27, 2018. Available here

Image courtesy:

1. ”Borazine-dimensions-2D” By Hbf878 - Own work, (CC0) via Commons Wikimedia
2. "Benzene representations" By Vladsinger - Own work (CC BY-SA 3.0) via Commons Wikimedia