SeOF2 Lewis structure

SeOF₂ (seleninyl fluoride) has one selenium atom, one oxygen atom, and two fluorine atoms.

In SeOF₂ Lewis structure, there is one double bond and two single bonds around the selenium atom, with one oxygen atom and two fluorine atoms attached to it. Each fluorine atom has three lone pairs, the oxygen atom has two lone pairs, and the selenium atom has one lone pair.

Alternative method: Lewis structure of SeOF₂

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, both selenium and oxygen lie in group 16, and fluorine lies in group 17.

Hence, both selenium and oxygen have six valence electrons, and fluorine has seven valence electrons.

Since SeOF₂ has one selenium atom, one oxygen atom, and two fluorine atoms, so…

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

And the total valence electrons = 6 + 6 + 14 = 26

Learn how to find: Selenium valence electrons, Oxygen valence electrons, and Fluorine valence electrons

• Second, find the total electron pairs

We have a total of 26 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 = 26 ÷ 2 = 13

• Third, determine the central atom

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

Since selenium is less electronegative than oxygen and fluorine, assume that the central atom is selenium.

Therefore, place selenium in the center and oxygen and fluorine on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 13 electron pairs. And three bonds are already marked. So we have to only mark the remaining ten electron pairs as lone pairs on the sketch.

Also remember that selenium is a period 4 element, so it can keep more than 8 electrons in its last shell. And both (oxygen and fluorine) are the period 2 elements, so they can not keep more than 8 electrons in their last shell.

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

So for oxygen and each fluorine, there are three lone pairs, and for selenium, there is one lone pair.

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 selenium atom, formal charge = 6 – 2 – ½ (6) = +1

For oxygen atom, formal charge = 6 – 6 – ½ (2) = -1

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

Here, both selenium and oxygen atoms have charges, so mark them on the sketch as follows:

The above structure is not a stable Lewis structure because both selenium and oxygen atoms have charges. Therefore, reduce the charges (as below) by converting lone pairs to bonds.

Convert a lone pair of the oxygen atom to make a new Se — O bond with the selenium atom as follows:

Final structure

The final structure of SeOF₂ involves a central selenium atom connected to one oxygen atom and two fluorine atoms. In this configuration, the selenium atom serves as an exception to the octet rule, utilizing an expanded valence shell to accommodate ten electrons through a double bond with the oxygen atom, single bonds with both fluorine atoms, and one lone pair. Each fluorine atom fulfills its octet by maintaining three lone pairs, while the oxygen atom retains two lone pairs alongside the double bond. This arrangement is the most stable because it results in formal charges of zero for all atoms involved, representing the most energetically favorable state for the molecule. Thus, this specific electronic distribution serves as the definitive and most accurate Lewis representation of selenium oxyfluoride.

Next: SBr₆ Lewis structure

External links

• https://www.chegg.com/homework-help/questions-and-answers/draw-lewis-structure-seof2-window-answer-questions-follow-q33240490
• https://oneclass.com/homework-help/chemistry/7028087-seof2-lewis-structure.en.html
• https://www.answers.com/Q/What_is_the_Lewis_structure_for_SeOF2