Simple Method for writing Lewis Structures for N2O2

Lewis Dot Structures of N₂O₂

A simple procedure for writing Lewis structures is given in a previous article entitled “Lewis Structures and the Octet Rule”. Several worked examples relevant to this procedure were given in previous posts please see the Sitemap - Table of Contents (Lewis Electron Dot Structures).

Another example  for writing Lewis structures following the above procedure is given below.

Let us consider the case of the dot structures of dinitrogen dioxide N₂O₂. Dinitrogen dioxide is the brown film we see in the atmosphere all over highly polluted cities. The resonance structures for N₂O₂ are as follows:

 

Step 1: Connect the atoms with single bonds. The central atoms are the nitrogen atoms.

 

Step 2: Calculate the # of electrons in π bonds (multiple bonds) using formula (1) in the article entitled “Lewis Structures and the Octet Rule” :

Where n in this case is 4 since N₂O₂ consists of four atoms. Where V = (5 + 5 + 6 + 6 ) = 22

Therefore, P = 6n + 2 – V = 6 * 4 + 2 – 22 = 4

So there are 4π electrons in N₂O₂ and that means 2 double bonds or a triple bond must be added to the structure in Step 1.

Step 3 & 4: The Lewis structures for N₂O₂ are as follows:

Figure 1: Lewis structures for N₂O₂. Structure #1 is the only experimentally observed structure. Structure #4 is the least plausible since O the most electronegative of the elements in the above structure has a + charge and N the least electronegative of the atoms present a – charge.