Question

Identify the false statement. (1) Borazole is isostructural with benzene. (2) Borozole contains \(\mathrm{B}, \mathrm{H}\) and \(\mathrm{N}\). (3) Both borazole and benzene are equally aromatic. (4) Borazole participate in addition reaction faster than benzene.

Short answer

Statement (3) is false.

Step-by-step solution

Analyze Statement (1)

Borazole, also known as borazine, has a similar structure to benzene. Both have a six-membered ring structure with alternating double bonds. Thus, statement (1) is true because they are isostructural.

Analyze Statement (2)

Borazole contains the elements boron (B), hydrogen (H), and nitrogen (N). Therefore, statement (2) is correct.

Analyze Statement (3)

Benzene is known to be highly aromatic due to its delocalized \( \text{π} \)-electrons. Borazole, while having a similar ring structure, is less aromatic compared to benzene because the electron distribution is uneven due to the differences in electronegativity of B and N. Hence, statement (3) is false.

Analyze Statement (4)

Borazole can participate in addition reactions more readily than benzene because the B-N bonds are weaker compared to C-C bonds in benzene, making statement (4) true.

Key concepts

isostructurality

Borazole, also known as borazine, is isostructural with benzene. This means that both molecules share the same structural framework. Borazole has a six-membered ring, similar to benzene, with alternating single and double bonds.

However, the key difference lies in the atoms that make up these rings. Benzene consists solely of carbon and hydrogen atoms, while borazole includes boron (B), nitrogen (N), and hydrogen (H) atoms. Despite this difference, the overall geometric structure remains similar.

This isostructurality is significant because it implies that both compounds will have similar external shapes and bonding patterns, which can affect their physical and chemical properties in comparable ways. Knowing this similarity helps in understanding their behavior in chemical reactions and when comparing other structural features.

aromaticity comparison

Aromaticity is a concept used to describe the stability that certain planar (flat) ring structures gain from the delocalization of π-electrons. Benzene is a classic example of an aromatic molecule. It is highly stable due to the delocalized π-electrons forming a continuous ring above and below the planar carbon atoms.

In contrast, while borazole mirrors benzene's structure, it is not as aromatic. This reduced aromaticity in borazole stems from the differing electronegativities of its constituent atoms—boron and nitrogen. Due to the differences in electronegativity, the electron cloud in borazole is not as evenly distributed as in benzene. This uneven distribution leads to decreased aromatic stabilization compared to benzene.

Understanding this difference in aromaticity is crucial because it affects how these molecules react chemically and their overall stability. Less aromatic compounds generally are more reactive since they do not benefit as much from the stabilizing effects of aromaticity.

chemical reactivity in addition reactions

Addition reactions involve the addition of atoms or groups of atoms to a molecule. In chemistry, the reactivity of a molecule in these reactions often hinges on how easily its bonds can be broken.

For benzene, the carbon-carbon (C-C) bonds are quite strong, conferring high stability and making it less reactive in addition reactions. Benzene generally prefers to undergo substitution reactions, maintaining its aromatic ring structure.

Borazole, however, exhibits higher reactivity in addition reactions compared to benzene. The B-N bonds in borazole are weaker than the C-C bonds in benzene. This bond weakness makes it easier for borazole to participate in addition reactions, where new groups can add across the B-N bond.

This increased reactivity is an essential factor to take into account for synthetic chemistry. The behavior of borazole in addition reactions can be advantageous or disadvantageous depending on the desired chemical process and target compounds.