Why is it important to describe the resonance structures in molecules such as ozone, #O_3#, and the organic molecule benzene, #C_6H_6#?

Question

Lucy Alessi · Accepted Answer

Because it helps to explain and rationalize experiment; if you like it explains reality.

Ozone is a bent molecule. That's the experimental fact. A Lewis structure of #O=stackrel(+)O-O^-# in which there are 3 regions of electron-density around the central atom explains this geometry. It also explains the trigonal planar geometry of #CO_3^(2-)#. The benzene molecule, #C_6H_6#, crops up persistently in organic chemistry. It is reactive under certain circusmtances, but not as reactive and not reactive in the same way as an olefin or an alkyne. Our ideas of resonance can help rationalize the observed reactivity. The idea of #6# #pi# electrons delocalized around a 6-membered ring can be extended to inorganic chemistry. Borazine, #B_3N_3H_3#, a benzene analogue, is isostructural and isoelectronic with benzene, and has similar aromatic chemistry.

Delilah Anderson · Answer

undefined It is important to describe the resonance structures in molecules such as ozone (O3) and benzene (C6H6) because they help explain the observed stability and properties of these molecules. Resonance structures provide insight into the delocalization of electrons within the molecule, leading to a more accurate representation of its electronic structure. In the case of ozone, the resonance structures show how the π electrons are delocalized between the oxygen atoms, resulting in a more stable molecule. Similarly, in benzene, the resonance structures illustrate the delocalization of π electrons around the ring, which contributes to the unique stability and reactivity of the molecule. Understanding resonance structures is crucial for predicting and explaining the chemical behavior of these molecules in various reactions and contexts.