Lewis Dot Structure of thiocyanate (SCN-) - #46

A simple procedure for writing co valent Lewis Structures was 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).

Let us consider the case of  SCN^- 

 

Step 1: Connect the atoms with single bonds:

Fig. 1:  The SCN- atoms connected with single bonds

 Step 2:  Calculate the # of electrons in π bonds (multiple bonds) using  formula (1): 

Where n in this case is 3. Where V = (6 + 4 + 5) – (-1) = 16 , V is the number of valence electrons of the molecule.

Therefore, P = 6n + 2 – V = 6 * 3 + 2 – 16  = 4   \  So, there are :  2 double bonds or a triple bond.

Step 3 & 4: The  resonance structures of  SCN^-  are as follows:

Fig. 2:  Lewis structures of the thiocyanate ion SCN^-