Structure, Polarity and Hybridization of ClO2- Lewis Structure

Chlorine dioxide’s molecular formula, ClO2, is often utilised in water treatment. It’s significantly superior to chlorine because it’s more water-soluble, doesn’t hydrolyze, and stays in solution as a gas.

Chlorite is the ionic form of chlorine dioxide with the chemical formula ClO2 (ClO2-). Chlorine dioxide, often known as chlorite, is a potent oxidising agent, as evidenced by its chemical formula.

During an oxidation-reduction or redox reaction, chlorine dioxide tends to be reduced and deliver oxygen to various substrates.

Chlorine dioxide in an ionic state is a powerful oxidant of chlorine oxyanions, based on this information.

This chemical was recently in the news because of a false promise that it might cure coronavirus.

This chemical should be examined in greater detail.

Chlorine Dioxide Lewis Structure (ClO2-)

Valence electrons are shown in the Lewis structure as they participate in the formation of bonds to create a new molecule with different features.

Chlorine dioxide’s structure can be drawn by first drawing a Lewis structure for all the relevant elements.

For Chlorine, use

Nucleus with atom number 17

1s2 2s2 2p6 3s2 3p5 = Electronic Configuration

Electrons of Valence = 7

When it comes to Oxygen,

The number of atoms in a molecule is 8

1s2 2s2 2p4 = Electronic Configuration

Electrons of Valence = 6

Now that we know that chlorine dioxide has 20 valence electrons, it will be easy to draw the Lewis structure of the molecule.

ClO2 only has 19 valence electrons, which may be a source of confusion for some.

As a powerful anion and oxidising agent, chlorine dioxide is critical here.

Due to the unstable nature of chlorine dioxide, it is most commonly seen as ClO2- during the bonding process. Chlorine dioxide and chlorite have valence electrons of 20 because of this.

Chlorine dioxide’s Lewis structure will have a valence electron count of 20.

Let’s see how to draw the Lewis structure of chlorine dioxide by going through these steps:

The first step is to determine how many valence electrons there are in a single molecule of chlorodioxide.

Chlorine contains seven valence electrons, while oxygen has six valence electrons, thus the total number of electrons is twenty.

Chlorine dioxide has two oxygen molecules, so the total number of oxygen molecules is 19.

There’s one more valence electron accessible because chlorine dioxide exists as ClO2- during the bonding process.

So, a chlorine dioxide or chlorite molecule has a total of 20 valence electrons.

To further stabilise the molecule, locate additional valence electrons.

The octet rule states that any element must have eight valence electrons in order to be fully electrical.

The chlorine atom has an abnormality in that it is able to expand its octet to accommodate extra valence electrons in this case. It’s a great illustration of how chemistry is full of anomalies!

The third group of the periodic table contains chlorine. For a chemical structure that is stable, the third group can expand its octet and accommodate more valence electrons.

As a result, if the enlarged octet anomaly in chlorine atom had not occurred, the total number of valence electrons required by one chlorine dioxide would have been 24 rather than the current 26.

Anatomy and skeleton of ClO2

Formal charge distribution can help us determine the stability of the lewis structure of chlorine dioxide depicted in the image above.

Each molecule strives for a stable structure that can only be achieved with a charge distribution of 0 formal volts.

The formal charge distribution of the chlorine dioxide molecule must now be calculated:

valence electrons – non-bonding electrons – 12 bonding electrons = valence formal charge

For Chlorine, use

Amount of Charge = 7 – 4 – 4/2 = 1

When it comes to Oxygen,

2/2 − 2/6 Equals -1 in the formal charge

Here, the +1 formal charge of the chlorine atom cancels out the -1 formal charge of one of the oxygen atoms.

A formal charge of -1 stays on another oxygen atom as a result of this.

As a result, the above Lewis structure is unstable, as another Lewis structure exists in which the formal distribution of some participating atoms is zero.

Consider this ClO2- molecule’s correct Lewis structure:

Let’s find the molecule’s formal charge distribution.

valence electrons – non-bonding electrons – 12 bonding electrons = valence formal charge

For Chlorine, use

Zero is the formal charge.

When it comes to Oxygen,

2/2 − 2/6 Equals -1 in the formal charge

When it comes to Oxygen,

Calculate your formal charge by subtracting 6 from the total and multiplying it by 4/2.

The formal charge distribution on two atoms in this structure is zero, which makes it more appropriate.

The formation of a double bond between an oxygen and a chlorine atom can be explained by carefully examining the formal charge distribution.

Identifying the type of bond formation in a chlorine oxide is step four.

Chlorine and oxygen make a single bond, while another oxygen atom forms a double bond with chloride.

The reason for this is found in the distribution of formal charges, which forces the development of a double bond and a single one.

Bond formation occurs with oxygen atoms even though new structures are more stable than the old ones.

Find the centre atom in step 5.

Because chlorine is the only atom in the chlorine dioxide molecule, it is the centre atom.

Furthermore, because it must form the most bonds, the atom with the lowest electronegativity becomes the centre atom.

Thus, chlorine is the primary atom.

Chlorine Dioxide Molecular Structure and Dynamics

According to the Lewis structure, chlorite ion or chlorine dioxide has three atoms and is bent.

The chlorine atom has lone pairs of valence electrons, and each chlorine and oxygen atom has an unequal bond type.

The Valence Shell Electron Pair Repulsion (VSEPR) Theory or the AXN method can be used to study this in further depth.

As a result of this idea, the bond angle is a little smaller than the standard 109°, owing to two lone pairs of electrons on the chlorine nucleus.

One sigma bond is all that a single bond has, however two sigma bonds and two pi bonds make up a double bond.

However strong one would think of the sigma bond, oxygen only forms bonds with other atoms in the vicinity of the chlorine atom it is linked to via a single bond. A double bond between chlorine and oxygen atoms is extremely stable, making it difficult for it to become excited.

Because it is unstable and requires additional valence electrons to attain a stable configuration, the (-) electron on the oxygen atom is responsible for the formation of the bond.

Due to its core atom’s two linked atoms and two lone pairs of valence electrons, chlorine dioxide’s general formula is AX2N2.

As a result, chlorine dioxide’s molecular geometry is twisted and its electron geometry is tetrahedral.

Furthermore, the AXN approach allows us to estimate the hybridization of the central atom in chlorine dioxide, which is Sp3.

Synergism between chlorine dioxide and other compounds (ClO2)

Chlorine hybridization is clearly sp3 based on the AXN technique.

There are two Lewis structures where chlorine and both oxygen atoms form double bonds, and the hybridization of the chlorine atom will be sp2. This is vital to understand.

Because chlorine dioxide exists in the ClO2-form, a Lewis structure like this is unusual.

In the chlorite ion, one 2s and three 2p orbitals are mixed and intermixed to generate four new hybrid orbitals of identical energy.

Head-on overlapping occurs in the sigma bond but in the pi bond, lateral overlap occurs.

Head-on overlapping makes the sigma bond more durable than the pi bond, while lateral overlapping of the pi bond is weaker.

In Chlorine Dioxide, there is polarity (ClO2)

A powerful anion, chlorine dioxide is polar because it exists in the ionic form.

In this scenario, the rule of electronegativity difference will not be applied.

Because chlorine dioxide is a strong anion, its electronegativity differs from that of oxygen by less than 0.4%, making it polar.

The qualities and applications of this substance should be examined as well.

Chlorine Dioxide’s properties are described here (ClO2)

Molecule NameChlorine dioxide
Chemical FormulaClO2
Molecular GeometryBent
Electron GeometryTetrahedral
Bond Angle<109°
Available Valence Electrons20

Chlorine Dioxide: Its Many Uses

  1. It is used in food processing in order to extend the shelf life of the product.

Mold removal is one of its primary applications.

  1. It is used to control the odour.

Dental professionals use it in a variety of procedures.

Vehicles, floors, air, and swimming pools all benefit from its antimicrobial properties as well.

For wound care, it’s a must-have item.

It’s a powerful bleaching agent, so be careful with it.


  1. Chlorite, the ionic form of chlorine dioxide, is a powerful anion.

Chlorine dioxide has a curved chemical structure with a bond angle that is less than 109 degrees.

3a. The hybridization of chlorine dioxide and its ion is 2a and 3a, respectively.

A molecular orbital diagram can be used to study the hybridization in further depth.

The chlorine dioxide ion has a formal charge distribution of a negative one (-1).

Using Valence Bond Theory, one can go deeper into the process of hybridization (VBT).

Because of its high oxidising power, chlorine dioxide is a polar molecule.

Read more: Molecular Geometry, Hybridization, and Polarity of C2H5OH Lewis Structure

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.


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