The process of merging two atomic orbitals to form a new type of hybridised orbitals is known as hybridization. As a result of this intermixing, hybrid orbitals with dramatically diverse energies, geometries, and so on are prevalent.. Atomic orbitals of the same energy level are principally responsible for hybridization. If their energies are equal, both completely filled and half-filled orbitals can participate in this process. Hybridization is a valence bond theory extension that helps with bond formation, bond energy, and bond length.

Hybridization Types

Different types of hybridization are possible between an atom’s s, p, d, and f orbitals based on the atomic orbitals that overlap to generate hybridised orbitals. In addition, the total number of molecular orbitals created equals the total number of contributing orbitals.

Hybridization of sp

• An sp hybridised orbital is generated by overlaying a single s-orbital and a single p-orbital, as the name implies.
• As a result of this overlap, three linear sp hybridised molecular orbitals form. The orbitals are arranged in such a way that they form a 180-degree angle.
• For example, the carbon atom in a molecule of carbon dioxide is sp hybridised.

The Lewis structure for CO₂ must first be drawn.

The steric number (SN) can be used to determine the hybridization of an atom, according to VSEPR theory.

SN equals the sum of the number of lone pairs and the number of atoms that are directly connected to the atom.

sp hybridization corresponds to SN=2.

sp² hybridization corresponds to SN=3.

The SN=2 of the C atom may be seen. It does not have any lone pairs, yet it is connected to two other atoms.

It has sp hybridization.

SN=3 is assigned to each O atom. It possesses two one-pair bonds and is connected to one C atom.

The oxygen atoms, like the carbon atoms, hybridise to produce the strongest connections.

The electron configuration of O’s valence electrons is [He]2s²2p⁴.

It will produce three equivalent sp² hybrid orbitals by accommodating the two lone pairs and the bonding pair.

Lone pairs are found in two of the sp² orbitals, while the remaining sp2 orbital and the unhybridized p orbital each have one electron.

The C=O bond of formaldehyde, which is comparable to the right-hand side of the O=C=O molecule, demonstrates this arrangement.

On the left side of the O=C=O molecule, a similar arrangement exists, but the bond is horizontal rather than vertical.

sp2 Hybridization

• A single s-orbital joins with two p-orbitals to generate a trigonal planar structured hybridised orbital in sp² hybridization.
• Because the hybridised orbitals form a 120-degree angle, the structure appears to be a triangle.
• For instance, the boron atom in the BF₃ molecule is sp² hybridised.

 sp3 Hybridization

• Methane is a well-known example of a carbon atom with an sp³ hybridised orbital.
• Four sp³ hybridised orbitals are formed when three p-orbitals unite with one s-orbital; these orbitals combine with the s-orbitals of four hydrogen atoms to produce the structure of a methane molecule.
• Sp³ hybridised orbitals create a tetrahedral structure with a 109.5 degree angle between them.

sp³d Hybridization

• The overlapping of one s-orbital, all three p-orbitals, and one of the five d-orbitals results in sp³d hybridised orbitals.
• The five hybridised orbitals have a trigonal bipyramidal structure.
• The phosphorus atom in a PF₅ molecule is an example of an sp3d hybridised orbital.

sp³d² Hybridization

• In a molecule of SF₆, all of the sulphur atom’s molecular orbitals involved in bond formation are sp³d² hybridised.
• One s-orbital, three p-orbitals, and two d-orbitals combine to generate these six hybridised molecular orbitals. The hybridised orbitals’ structure is octahedral symmetrical, and the angles formed are all perpendicular to one another.

Types of Bond

All of the hybridised orbitals generated have the same energy level, and these hybridised orbitals are what cause a molecule’s bond to form. There are two sorts of bonds established depending on the type of overlap:

• The linear overlap of two hybridised orbitals creates the sigma bond. This is also known as head-to-head overlap. Consider the following scenario: The linear overlapping of one carbon and four hydrogen molecular orbitals forms a sigma bond in methane.
• Pi-bond: The pi-bond is produced when orbitals intersect on the lateral side. This is also known as side-by-side overlap. An ethene molecule, for example, has one sigma and one pi link between the carbon and hydrogen atoms.

Summary

Conclusion

Hybridization of orbitals is preferred because hybridised orbitals are more directed, resulting in more overlap when forming bonds, resulting in stronger bonds. When hybridization occurs, this results in more stable molecules.