Molecular Orbitals

The molecular orbital function may be used to compute the region in a molecule where the likelihood of finding an electron is greatest. Molecular orbitals are mathematical functions that represent the wave behaviour of electrons in a particular molecule. These orbitals can be formed by combining hybridized orbitals of atomic orbitals from each atom in the molecule. Molecular orbitals give a useful model for demonstrating molecule bonding using molecular orbital theory.

Molecular Orbital Types

According to molecular orbital theory, there are three basic types of molecular orbitals created by the linear combination of atomic orbitals. These orbitals are described in more depth below.

• Molecular Orbitals with Anti-Bonding

The electron density in anti-bonding molecular orbitals is concentrated behind the nuclei of the two bonding atoms. As a result, the nuclei of the two atoms are pushed apart from one another. These orbitals erode the link between two atoms.

• Non-Bonding Molecular Orbitals

Due to a total absence of symmetry in the compatibility of two bonding atomic orbitals, the molecular orbitals created have no positive or negative interactions with each other in the case of non-bonding molecular orbitals. These orbitals have no effect on the link between the two atoms.

Molecular Orbital Formation

An atomic orbital is a type of electron wave, and the waves of two atomic orbitals can be in phase or out of phase.

Bonding Molecular Orbitals Characteristics

• The likelihood of locating the electron in the bonding molecular orbital’s internuclear region is larger than that of combining atomic orbitals.
• The electrons in the bonding molecular orbital attract the two atoms to one another.
• Because of attraction, the bonding molecule orbital has lower energy and hence better stability than the combining atomic orbitals.
• They are created as a result of the cumulative influence of the atomic orbitals, with the amplitude of the resultant wave given by ф = ψA +ψB.
• They are represented by the symbols,σ, π and δ.

Anti-bonding Molecular Orbitals Characteristics

• In the anti-bonding molecular orbitals, the likelihood of finding an electron in the internuclear area drops.
• Because of the electrons in the anti-bonding molecular orbital, the two atoms repel each other.
• Because of the repulsive interactions, the anti-bonding molecular orbitals have more energy and less stability.
• They are created by the atomic orbitals’ subtractive action. The new wave’s amplitude is determined by ф’= ψA – ψB.
• They are represented by the symbols,σ*, π*, and δ*.

Also read: JEE Advanced Sample Papers

FAQs

What is the distinction between Sigma Bond and Pi Bond?

The linear overlapping of two atoms' atomic orbitals results in the formation of a sigma bond. The overlap of electrons in a pi bond happens both above and below the axis connecting the nuclei of two atoms.

Why are antibonding orbitals more energetic?

Bonding molecular orbitals are usually less energetic than anti-bonding molecular orbitals. This is due to the fact that in the case of bonding Molecular Orbitals, the electrons in the orbital are attracted by the nuclei, however, the nuclei reject each other in the case of anti-bonding Molecular Orbitals.