SBr2 Lewis structure

SBr₂ (sulfur dibromide) has one sulfur atom and two bromine atoms.

In the SBr₂ Lewis structure, there are two single bonds around the sulfur atom, with two bromine atoms attached to it. Each bromine atom has three lone pairs, and the sulfur atom has two lone pairs.

Alternative method: Lewis structure of SBr₂

Rough sketch

• First, determine the total number of valence electrons

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

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

Since SBr₂ has one sulfur atom and two bromine atoms, so…

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

And the total valence electrons = 6 + 14 = 20

Learn how to find: Sulfur valence electrons and Bromine 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 bromine, assume that the central atom is sulfur.

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

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 10 electron pairs. And two S — Br 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 bromine is a period 4 element, so it can keep more than 8 electrons in its last shell.

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

So for each bromine, 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 bromine atom, formal charge = 7 – 6 – ½ (2) = 0

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

Final structure

The final structure of SBr₂ consists of a central sulfur atom linked to two bromine atoms through single covalent bonds. In this configuration, the sulfur atom satisfies the octet rule by forming two bonds and maintaining two lone pairs. Within this layout, each bromine atom also fulfills its octet by retaining three lone pairs alongside its single shared bond. This arrangement represents the most stable state for the molecule because it results in a formal charge of zero for every atom involved. Accordingly, this specific electronic distribution serves as the definitive and most accurate Lewis representation of sulfur dibromide.

Next: C₃H₆ Lewis structure

External video

• SBr2 Lewis Structure – How to Draw the Dot Structure for SBr2 (Sulfur dibromide) – YouTube • Wayne Breslyn

External links

• https://topblogtenz.com/sbr2-lewis-structure-molecular-geometry-polar-or-nonpolar-bond-angle/
• https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/SBr2-lewis-structure.html
• https://lambdageeks.com/sbr2-lewis-structure/
• https://sciedutut.com/sbr2-lewis-structure/