Dichlorine monoxide(OCl2) is an inorganic compound that is brown-yellow gas at room temperature. It has a molecular weight of 86.9054 g/mol. It has a melting point of -120.6℃ and a boiling point of 2.0℃. Belonging to the chlorine oxide family, OCl2 is soluble in both water and inorganic solvents.
It was first synthesized by Antoine Jérôme Balard in 1834.
Nowadays, dichlorine monoxide(OCl2) is synthesized by the reaction of chlorine gas with hydrated sodium carbonate at 20-30℃.
2 Cl2 + 2Na2CO3 + H2O ——> Cl2O + 2NaHCO3 + 2NaCl
2 Cl2 + 2NaHCO3 ——> Cl2O + 2CO2 + 2NaCl + H2O
The oxygen atom in the molecule is sp3 hybridized with a bent-shaped structure. The bond angle of OCl2 is 110.9⸰, which is slightly higher than the normal bond angle of 109⸰28’ due to the steric repulsion between the bulky chlorine atom.
So, is OCl2 Polar or nonpolar? OCl2 is a polar molecule because of its bent shape. The two lone pairs present on the oxygen atom cause its bent shape. Corresponding to this shape, the net dipole moment in OCl2 is in the upward direction making the molecule polar.
Dichlorine monoxide(OCl2) because of its wide uses and fascinating properties is an interesting compound. Given below is a detailed explanation of the polarity of OCl2 and various other concepts required to understand it better. So, what are you waiting for? Read below to satisfy your hunger for knowledge.
Differences between Polar and Nonpolar Molecules
Polar molecules are the molecules that have considerable electronegativity differences between their atoms and have a net dipole moment.
Nonpolar molecules are the molecules for which the difference in electronegativity between the atoms is negligible and have zero dipole moment.
Let us see some of the basic yet key differences between these two:
Polar molecules generally have significant electronegativity differences between their component atoms and asymmetric arrangement. They may also possess lone pairs of electrons on the central atom.
On the other hand, nonpolar molecules are mostly symmetric in arrangement with negligible electronegativity difference.
The second most important and significant difference is the dipole moment.
Polar molecules possess a net dipole moment i.e. the separation of charge in the molecule. Eg: H2O, HF, OCl2, etc.
Nonpolar molecules have a net-zero dipole moment. It is to be remembered that molecules having significant electronegativity differences may be nonpolar because of their geometry, which cancels the dipole moment.
For eg: CO2 is nonpolar because the dipole moment cancels each other on both sides resulting in a zero dipole moment, despite having a significant electronegativity difference.
Polar molecules are soluble in polar solvents whereas nonpolar molecules are soluble in nonpolar solvents.
Bonds: Classification and Characteristics
With billions of compounds present today, it becomes important and necessary for us to understand what holds these chemical compounds together.
Chemical bonds are the forging connections between atoms in a molecule. With varying atoms, the properties and the nature of these bonds also change.
Let’s see in brief about what is between these chemical bonds and their classification:
1. Ionic Bond
- In ionic bonding, there is a complete transfer of the valence electron from the metal atom to the nonmetal atom. Both the atoms have high electronegativity differences leading to ionic bonding.
- Ionic bonding results in the formation of cations and anions from the metal and nonmental atom respectively.
- Ionic bonds are a lot stronger than covalent bonds.
- Compounds formed by ionic bonding have high melting and boiling points. Eg. NaCl, Mg(OH)2, KOH, etc.
2. Covalent Bond
- A covalent bond, unlike an ionic bond, involves sharing of electrons between the atoms. The shared electrons are called shared pairs.
- Covalent bonding is achieved in molecules with less electronegativity difference and aims at minimum repulsion between the atoms.
- Covalent bonds are weaker than ionic bonds.
- They are further classified as polar and nonpolar covalent bonds depending upon the distribution of the electron cloud based on the difference in their electronegativity. Eg. O2, Cl2, PCl3, etc.
What causes polarity in bonds?
The sole reason for the polarity of bonds is the interaction of atoms with different electronegativities. When atoms with different electronegativities form a bond, there is a shift in the electron cloud to the atom having higher electronegativity.
Let us take the example of Hydrofluoric Acid(HF). The electronegativity difference between Fluorine(4.0) and Hydrogen(2.2) is 1.8.
Corresponding to this difference, the electron cloud shifts to the fluorine atom resulting in a partial negative charge -δ on the fluorine atom and a partial positive charge +δ on the hydrogen atom.
This separation in charge between the atoms results in the polarity of the molecule.
Why is OCl2 Polar?
The polarity of molecules is mainly due to the presence of electronegativity between the atoms and the net dipole moment.
Considering OCl2(Oxygen dichloride), the oxygen atom is sp3 hybridized having two lone pairs on the oxygen atom. The molecular geometry of OCl2 is bent-shaped with an angle of 110.9⸰ between the Cl-O-Cl bond.
Observing the dipole moment in OCl2 in the below diagram, we see that oxygen(3.44) being more electronegative than chlorine(3.16) attracts the electron pairs towards itself, resulting in a dipole moment towards oxygen.
The two lone pairs present on the oxygen atom also have their dipole moment in the upward direction. Hence, the net dipole moment of the O-Cl bonds and the lone pairs is in the upward direction.
Because of this net dipole moment which is a result of the bent shape of OCl2, the molecule is polar in nature.
For detailed information about the bonding and structure, you may refer to OCl2 Lewis Structure, Geometry, Hybridization.
1. OCl2 is used extensively as a chlorinating agent. It can be used for a ring or side-chain chlorination of aromatic substrates. Dichlorine monoxide is the active species in the reactions of HOCl with aromatic compounds and olefins.
2. OCl2 under sunlight undergoes photochemical decomposition forming O2 and Cl2 as products.
2OCl2 —–> 2Cl2 + O2
3. Dichlorine monoxide(OCl2) upon reaction with metal halides, releases Cl2 and produces oxyhalides.
TiCl4 + OCl2 ——> TiOCl2 + 2Cl2
4. Being highly soluble in water, OCl2 is used in the chlorination of drinking water.
5. Dichlorine monoxide(OCl2) is also used as an intermediate in the manufacture of Calcium Hypochlorite and also as a sterilizing agent for space applications.
6. Dichlorine monoxide(OCl2) is used as an oxidizer and chlorinating agent.
The article gives you an explanation of how the polarity rises in the OCl2 molecule. And the factors that enhance the polarity in a molecule.
The electronegativity differences between two atoms, geometrical structure are the main aspects that contribute to the polar nature of any molecule.
If you have any questions in your mind. Ask them in the comment section.