SF2 Lewis structure

SF₂ (sulfur difluoride) has one sulfur atom and two fluorine atoms.

In the SF₂ Lewis structure, there are two single bonds around the sulfur atom, with two fluorine atoms attached to it. Each fluorine atom has three lone pairs, and the sulfur atom has two lone pairs.

Alternative method: Lewis structure of SF₂

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, sulfur lies in group 16, and fluorine lies in group 17.

Hence, sulfur has six valence electrons and fluorine has seven valence electrons.

Since SF₂ has one sulfur atom and two fluorine atoms, so…

Valence electrons of one sulfur atom = 6 × 1 = 6
Valence electrons of two fluorine atoms = 7 × 2 = 14

And the total valence electrons = 6 + 14 = 20

Learn how to find: Sulfur valence electrons and Fluorine valence electrons

• Second, find the total electron pairs

We have a total of 20 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 20 ÷ 2 = 10

• Third, determine the central atom

We have to place the least electronegative atom at the center.

Since sulfur is less electronegative than fluorine, assume that the central atom is sulfur.

Therefore, place sulfur in the center and fluorines on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 10 electron pairs. And two S — F bonds are already marked. So we have to only mark the remaining eight electron pairs as lone pairs on the sketch.

Also remember that sulfur is a period 3 element, so it can keep more than 8 electrons in its last shell. And fluorine is a period 2 element, so it can not keep more than 8 electrons in its last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are fluorines.

So for each fluorine, there are three lone pairs, and for sulfur, there are two lone pairs.

Mark the lone pairs on the sketch as follows:

Formal charge

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For sulfur atom, formal charge = 6 – 4 – ½ (4) = 0

For each fluorine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, both sulfur and fluorine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of SF₂ comprises a central sulfur atom connected to two fluorine atoms through single covalent bonds. Within this configuration, the sulfur atom satisfies the octet rule by forming two bonding pairs and retaining two lone pairs. Each fluorine atom also fulfills its octet by maintaining three lone pairs of its own. This setup is the most stable because it results in formal charges of zero for all participating atoms, representing the most energetically favorable state for the molecule. Consequently, this specific electronic distribution serves as the definitive and most accurate Lewis representation of sulfur difluoride.

Next: IF₅ Lewis structure

External video

• SF2 Lewis Structure – How to Draw the Lewis Structure for SF2 – YouTube • Wayne Breslyn

External links

• https://geometryofmolecules.com/sf2-lewis-structure-polarity-and-bond-angles/
• https://topblogtenz.com/sf2-lewis-structure-molecular-geometry-polar-or-nonpolar-hybridization/
• https://techiescientist.com/sf2-lewis-structure/
• https://lambdageeks.com/sf2-lewis-structure/
• https://whatsinsight.org/sf2-lewis-structure-molecular-geometry-simple-steps/
• https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/SF2-lewis-structure.html
• https://sciedutut.com/sf2-lewis-structure/