Q2-57E - Organic Chemistry (Mcmurry)

Question

Draw as many resonance structures as you can for the following species, adding appropriate formal charges to each:

Step-by-Step Solution

Answer

1. Given structure nitromethane has two resonance structures
2. Given structure ozone has two resonance structures
3. Given structure diazomethane has two resonance structures

Step 1: Definition of resonance structures

Structures which are formed by the electronic displacement of 𝛑 bonds in a compound. Then the structures generated are known as resonance structures.

Formal charge (F.C) can be defined as the difference number of valence electrons and number of electrons present in the Lewis structure.

$\mathbf{F}\mathbf{.}\mathbf{C}\mathbf{=}[\mathbf{V}\left(\mathbf{electrons}\right)\mathbf{-}\mathbf{L}\left(\mathbf{electrons}\right)]$

V= valence shell

L= electrons present according to Lewis structures

Step 2: (a) Draw structure by the displacement of 𝛑 bonds

Above can be drawn by the electronic displacement of 𝛑 bonds only.

Step 3: Check the formal charge present on the individual atom

$\text{F.C=}\left[\text{V}\left(\text{electrons}\right)\text{-L}\left(\text{electrons}\right)\right]$

$\text{F.C on Nitrogen = 5 – 4 = 1}$

Step 4: (b) Draw structure by the displacement of 𝛑 bonds

Above structures can be drawn by the electronic displacement of 𝛑 bonds only.

Step 5: Check the formal charge present on the individual atom

$\text{F.C=}\left[\text{V}\left(\text{electrons}\right)\text{-L}\left(\text{electrons}\right)\right]$

$\text{F.C on Oxygen = 6 – 5 = 1}$

Step 6: (c) Draw structure by the displacement of 𝛑 bonds

Above structures can only be drawn by the electronic displacement of 𝛑 bonds only.

Step 7: Check the formal charge present on the individual atom

$\text{F.C=}\left[\text{V}\left(\text{electrons}\right)\text{-L}\left(\text{electrons}\right)\right]$

$\text{F.C on Nitrogen= 5 – 4 = 1}$(Non-terminal Nitrogen atom)