SF2 Lewis Structure, Molecular Geometry, Hybridization, Polarity, and MO Diagram

SF2 Lewis Structure

Sulfur Fluoride is a highly unstable inorganic compound. With a molar mass of 70.062 g/mol, this compound is made up of one Sulfur atom and two Fluoride atoms.

This compound is formed when sulfur dichloride reacts at low pressure with either potassium fluoride or mercury (||) fluoride.

SCl2   +   2KF   —–>    SF2     +    2 KCl
SCl2   +   HgF2    ——->    SF2    +    HgCl2

Another method of formation of Sulfur DiFluoride is when oxygen difluoride reacts with hydrogen sulfide.

OF2    +    H2S    ——>    SF2   +   H2O

The compound is not hazardous in nature and does not require special handling and storage.

However, under acute circumstances, the compound can cause respiratory irritation.

Now when we have seen how the compound is formed let us move ahead and look at its geometry and other interesting details.


Lewis Structure of SF2

Lewis Structure is nothing but an arrangement of valence electrons between different atoms. It is important to look at what the Lewis Structure of SF2 is so that we can move ahead and look at other aspects of it.

First, we will have to calculate the total number of valence electrons in this compound. Valence electrons of Sulfur are 6 in number. And, the valence electrons of Fluorine are 7 in number.

There are in total 2 atoms of Fluorine in this compound. Thus, The total number of valence electrons = Valence electrons of Sulfur + Valence electrons of 2 Fluorine atoms

= 6 + 2*7

= 20 valence electrons.

Therefore, the total number of valence electrons in Sulfur Difluoride is 20.

Now, these valence electrons take their place around the central atom. Here the central atom is Sulfur. This is because it is less electronegative than the other atom of the compound which is Fluorine.

SF2 lewis structure

Every atom needs to fill its outer shell to become stable.

Here Fluorine needs only one electron to complete its octet. Thus, the two atoms of Fluorine share one electron each with two atoms of Sulfur.

One pair of electron sharing means that only a single bond is formed between Sulfur and two atoms of Fluorine each.

You can understand and make Lewis’s structure when you know how many electrons are shared and how many electrons are left as lone pairs of electrons.

So, after two bonds are formed, out of 20 valence electrons only 16 valence electrons are left. Out of these 16 valence electrons, 4 are of sulfur and 6 are of each Fluorine atom.

Thus, there are two lone pairs of electrons on Sulfur that did not get to participate in bond formation.

And there are three lone pairs of electrons on each Fluorine atom, which makes it a total of six pairs of lone electrons for the SF2 compound as a whole.

This explains the Lewis structure of SF2, how the bonds are made, and how many lone pairs of electrons are there.
Now, let us move to what is the hybridization of SF2.


Hybridization of SF2

Hybridization is the concept of knowing and identifying that how many electrons are there in the different energy orbital.

There are four energy levels and each energy level can accommodate a different number of electrons. See the below-given chart to know about the capacity of each energy level.

In the first energy level, 2 electrons can fit. In the second energy level, 8 electrons can fit. And so on…


Sublevel energy levels

In the case of SF2, you can look at the below-given diagram to understand how the electrons are placed in different energy orbitals.

SF2 hybridization

The bond formation in SF2 is a single bond which means it is a sigma bond. Hybridization is related to the mixing of orbitals that are at different energies.

The electronic configuration of Sulfur is 1s2 2s2 2p6 3s2 3p4. First, the electrons are filled in 1s, then in 2s, and so on.

Similarly, the electronic configuration of Fluorine is 1s2 2s2 2p5. These configurations are decided on the basis of the number of electrons these elements have.

When we consider the electronic configuration of SF2 then it comes to 3s2 3Px2 3Py1 3Pz1. By that, we can deduce the hybridization of the compound, which comes as sp3.

Another way of finding the hybridization of SF2 is by calculating the steric number of SF2, which we can find by the following equation.

Steric number = Number of bonds on central atom + Number of lone pairs on the central atom.

Here the central atom is Sulfur.

And as we have seen there are two bonds and two lone pairs of electrons on the sulfur atom. Therefore, Steric number = 2+2 =4

Every number represents one energy orbital. Thus, here 4 deduce that four energy levels are going to be utilized.

Thus, the hybridization of SF2 is sp3.

Now when we know about the hybridization of the compound, we can move ahead and look at its molecular geometry.


Molecular Geometry of SF2

The molecular geometry of any compound is understood to know about the structure of the compound and how it appears in a plane.

This is generally calculated with the help of the VSEPR theory.

According to VSEPR theory, each atom in a compound is arranged in a way that the compound becomes stable in nature. The repulsion between the atoms and their corresponding electrons should be minimum and to achieve that a compound takes a unique shape.

This shape is decided on the basis of different factors like lone pairs of electrons, bonding electrons, etc. Here is a diagram to show you different arrangements that can be made between compounds.

VSEPR chart

Based on the lone pair of electrons and bonds that are formed we can identify what can be the molecular geometry of a compound.

So, for SF2 the central atom has 2 bonds and 2 lone pairs of electrons.

Thus, the molecular geometry is of the type AX2E2 which leads us to the conclusion that the compound is non-linear or is bent.

So, SF2 has a bent molecular geometry.

The bent structure is obtained due to the existence of lone pairs and bonds on the central atom. Due to which there are repulsions and these repulsive forces lead to bent geometry.


Bond Angle of SF2

Now as we have seen that the compound has a slight bent in its shape, this means that there is surely going to be some bond angle.

The angle that forms in SF2 is somewhere around 98 degrees.

Both Fluorine atoms are pushed downwards by Sulfur’s lone pairs which give us a bond angle varying between 180 degrees to 98 degrees.

SF2 Geometry


MO Diagram of SF2

MO diagrams are a good way to represent the different properties of a compound. These properties include shape, bond energy, bond angle, and more such things.

With the help of this diagram, we can showcase the energy that different energy orbital acquires and have.

Here is a MO diagram of another bent compound ie; bent shaped (SO2 molecule) and how the energies are distributed.

SO2 MO Diagram


Polarity of SF2

Now after we have seen every aspect of this compound from Lewis’s structure to molecular geometry, we can talk about its polarity.

Why knowing about the polarity of a compound is essential?

It is important to know about the polarity of any compound because by knowing about the polarity we come to know that whether the compound has a negative or positive charge. We come to know that how exactly atoms bond with each other, what is the attractive force that arises, and more.

We access the lone pairs on the atom, the shape, and other things while finding the polarity of a compound.
In the case of SF2, the lone pair of electrons put a repulsive force over the bonds formed between Sulfur and Fluorine.

Due to this, the Fluorine atoms are pushed down which gives the compound a bent shape.

Hence, the charge on the compound is not evenly distributed thus we can be sure that the dipole moment is not going to be zero.

As the shape is not linear and there is repulsion, we can surely say that the compound is Polar in nature.

You can also check the article on the polarity of SF2.



Let us now summarize all that we have learned and understood about the compound SF2.

SF2 has Sulfur as its central atom with two neighboring atoms of Fluorine. The compound is Polar in nature because the dipole moment between the Sulfur and Fluorine doesn’t cancel each other. The hybridization of this compound is sp3 and the molecular geometry is bent or non-linear in nature.

We hope that the article was insightful enough for you and that you got a good grasp of the discussed topic. In case you are stuck at any point you can reach out to us and we will be happy to help.

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