Molecular Orbital Configuration Of O2

What is Molecular Orbital Theory?

The Molecular Orbital Theory (oft abbreviated to MOT) is a theory on chemical bonding adult at the beginning of the twentieth century past F. Hund and R. Due south. Mulliken to describe the structure and backdrop of different molecules. The valence-bond theory failed to adequately explain how certain molecules incorporate 2 or more than equivalent bonds whose bond orders lie between that of a unmarried bond and that of a double bond, such as the bonds in resonance-stabilized molecules. This is where the molecular orbital theory proved to be more powerful than the valence-bond theory (since the orbitals described by the MOT reverberate the geometries of the molecules to which information technology is applied).

The key features of the molecular orbital theory are listed beneath.

The full number of molecular orbitals formed will always be equal to the total number of atomic orbitals offered past the bonding species.
There exist dissimilar types of molecular orbitals viz; bonding molecular orbitals, anti-bonding molecular orbitals, and non-bonding molecular orbitals. Of these, anti-bonding molecular orbitals volition always have higher free energy than the parent orbitals whereas bonding molecular orbitals will always take lower energy than the parent orbitals.
The electrons are filled into molecular orbitals in the increasing guild of orbital energy (from the orbital with the lowest energy to the orbital with the highest energy).
The almost effective combinations of atomic orbitals (for the formation of molecular orbitals) occur when the combining diminutive orbitals accept like energies.

In simple terms, the molecular orbital theory states that each atom tends to combine together and form molecular orbitals. As a effect of such organisation, electrons are found in various diminutive orbitals and they are usually associated with different nuclei. In brusk, an electron in a molecule tin be present anywhere in the molecule.

1 of the main impacts of the molecular orbital theory after its conception is that information technology paved a new style to sympathise the process of bonding. With this theory, the molecular orbitals are basically considered as linear combinations of atomic orbitals. The approximations are further done using the Hartree–Fock (HF) or the density functional theory (DFT) models to the Schrödinger equation.

Tabular array of Content

Linear Combination of Atomic Orbitals
Weather
Molecular Orbitals
Types
Germination of Molecular Orbitals
Bonding Molecular Orbitals
Anti-bonding Molecular Orbitals
Differences
Features of MOT

Molecular orbital theory approximation of the molecular orbitals every bit linear combinations of atomic orbitals can be illustrated as follows.

Molecular Orbital Theory

However, to understand the molecular orbital theory more clearly and in-depth, it is important to understand what atomic and molecular orbitals are first.

Video Lesson – Molecular Orbital Theory

Linear Combination of Atomic Orbitals (LCAO)

Molecular orbitals can generally exist expressed through a linear combination of diminutive orbitals (abbreviated to LCAO). These LCAOs are useful in the estimation of the formation of these orbitals in the bonding between the atoms that make upwardly a molecule.

The Schrodinger equation used to depict the electron behaviour for molecular orbitals tin can exist written in a method similar to that for atomic orbitals.

It is an approximate method for representing molecular orbitals. It's more of a superimposition method where constructive interference of two diminutive wave function produces a bonding molecular orbital whereas destructive interference produces non-bonding molecular orbital.

Too Read

Chemic Bonding
Covalent Bond
Fajan's rule
VSEPR Theory
Crystal Field Theory

Weather condition for Linear Combination of Atomic Orbitals

The atmospheric condition that are required for the linear combination of atomic orbitals are as follows:

Same Energy of Combining Orbitals

The diminutive orbitals combining to grade molecular orbitals should have comparable energy. This means that 2p orbital of an atom can combine with another 2p orbital of another atom merely 1s and 2p cannot combine together as they take observable energy difference.

Aforementioned Symmetry near Molecular Axis

The combining atoms should have the same symmetry around the molecular axis for proper combination, otherwise, the electron density will be sparse. For east.g. all the sub-orbitals of 2p have the same energy merely still, 2pz orbital of an cantlet can only combine with a 2pz orbital of another atom but cannot combine with 2px and 2py orbital equally they have a dissimilar axis of symmetry. In general, the z-axis is considered as the molecular axis of symmetry.

Proper Overlap between Atomic Orbitals

The two atomic orbitals will combine to course molecular orbital if the overlap is proper. Greater the extent of overlap of orbitals, greater volition exist the nuclear density betwixt the nuclei of the two atoms.

The status can be understood by two elementary requirements. For the formation of proper molecular orbital, proper energy and orientation are required. For proper energy, the two atomic orbitals should take the aforementioned free energy and for the proper orientation, the diminutive orbitals should have proper overlap and the same molecular axis of symmetry.

What are Molecular Orbitals?

The space in a molecule in which the probability of finding an electron is maximum tin can be calculated using the molecular orbital function. Molecular orbitals are basically mathematical functions that describe the moving ridge nature of electrons in a given molecule.

These orbitals can be constructed via the combination of hybridized orbitals or atomic orbitals from each atom belonging to the specific molecule. Molecular orbitals provide a nifty model via the molecular orbital theory to demonstrate the bonding of molecules.

Types of Molecular Orbitals

According to the molecular orbital theory, in that location be 3 primary types of molecular orbitals that are formed from the linear combination of atomic orbitals. These orbitals are detailed beneath.

Anti Bonding Molecular Orbitals

The electron density is concentrated behind the nuclei of the two bonding atoms in anti-bonding molecular orbitals. This results in the nuclei of the 2 atoms being pulled away from each other. These kinds of orbitals weaken the bond betwixt 2 atoms.

Not-Bonding Molecular Orbitals

In the instance of non-bonding molecular orbitals, due to a complete lack of symmetry in the compatibility of two bonding atomic orbitals, the molecular orbitals formed take no positive or negative interactions with each other. These types of orbitals practise not affect the bail between the ii atoms.

Germination of Molecular Orbitals

An atomic orbital is an electron wave; the waves of the two diminutive orbitals may be in phase or out of phase. Suppose Ψ_A and Ψ_B represent the aamplitude of the electron wave of the diminutive orbitals of the two atoms A and B.

Instance ane: When the two waves are in phase so that they add up and amplitude of the wave is Φ= Ψ_A + Ψ_B

Additive effect of electron wave - Molecular Orbital Theory

Case 2: when the 2 waves are out of phase, the waves are subtracted from each other so that the amplitude of the new wave is Φ ´= Ψ_A – Ψ_B

Subtractive effect of electron wave - Molecular Orbital Theory

Characteristics of Bonding Molecular Orbitals

The probability of finding the electron in the internuclear region of the bonding molecular orbital is greater than that of combining atomic orbitals.
The electrons present in the bonding molecular orbital result in the attraction between the ii atoms.
The bonding molecular orbital has lower energy as a result of attraction and hence has greater stability than that of the combining atomic orbitals.
They are formed past the additive effect of the atomic orbitals so that the amplitude of the new moving ridge is given by Φ= Ψ_A + Ψ_B
They are represented by σ, π, and δ.

Characteristics of Anti-bonding Molecular Orbitals

The probability of finding the electron in the internuclear region decreases in the anti-bonding molecular orbitals.
The electrons nowadays in the anti-bonding molecular orbital event in the repulsion between the ii atoms.
The anti-bonding molecular orbitals accept college energy because of the repulsive forces and lower stability.
They are formed by the subtractive effect of the diminutive orbitals. The aamplitude of the new moving ridge is given by Φ ´= Ψ_A – Ψ_B
They are represented by σ^∗, π^∗, δ^∗

Why are Antibonding Orbitals Higher in Free energy?

The energy levels of bonding molecular orbitals are ever lower than those of anti-bonding molecular orbitals. This is because the electrons in the orbital are attracted by the nuclei in the case of bonding Molecular Orbitals whereas the nuclei repel each other in the instance of the anti-bonding Molecular Orbitals.

Difference betwixt Bonding and Antibonding Molecular Orbitals

Molecular Orbital Theory
Bonding Molecular Orbitals	Anti-Bonding Molecular Orbitals
Molecular orbitals formed past the additive outcome of the atomic orbitals is called bonding molecular orbitals	Molecular orbitals formed by the subtractive effect of atomic is called anti-bonding molecular orbitals
Probability of finding the electrons is more in the example of bonding molecular orbitals	Probability of finding electrons is less in antibonding molecular orbitals. In that location is also a node between the anti-bonding molecular orbital between two nuclei where the electron density is cipher.
These are formed by the combination of + and + and – with – part of the electron waves	These are formed by the overlap of + with – part.
The electron density, in the bonding molecular orbital in the internuclear region, is high. Every bit a result, the nuclei are shielded from each other and hence the repulsion is very less.	The electron density in the antibonding molecular orbital in the internuclear region is very low and so the nuclei are straight exposed to each other. Therefore the nuclei are less shielded from each other.
The bonding molecular orbitals are represented by σ, π, δ.	The corresponding anti-bonding molecular orbitals are represented by σ∗ , π∗, δ∗.

The lowering of the energy of bonding molecular orbital than the combining atomic orbital is called stabilization free energy and similarly increase in free energy of the anti-bonding molecular orbitals is calleddestabilization energy.

Attempt this:Paramagnetic materials, those with unpaired electrons, are attracted by magnetic fields whereas diamagnetic materials, those with no unpaired electrons, are weakly repelled by such fields. By constructing a molecular orbital picture for each of the following molecules, determine whether it is paramagnetic or diamagnetic.

B₂
C₂
O₂
NO
CO

Features of Molecular Orbital Theory

The atomic orbitals overlap to class new orbitals calledmolecular orbitals.When two atomic orbitals overlap they lose their identity and form new orbitals chosenmolecular orbitals.
The electrons in the molecules are filled in the new free energy states called the Molecular orbitals similar to the electrons in an atom being filled in an energy state called atomic orbitals.
The probability of finding the electronic distribution in a molecule around its grouping of nuclei is given by the molecular orbital.
The two combining atomic orbitals should possess energies of comparable value and similar orientation. For example, 1s tin can combine with 1s and not with 2s.
The number of molecular orbitals formed is equal to the number of atomic orbitals combining.
The shape of molecular orbitals formed depends upon the shape of the combining diminutive orbitals.

According to the Molecular Orbital Theory, the filling of orbitals takes place according to the following rules:

Aufbau's principle: Molecular orbitals are filled in the increasing club of energy levels.
Pauli's exclusion principle: In an cantlet or a molecule, no two electrons can take the same set of four quantum numbers.
Hund's dominion of maximum multiplicity: Pairing of electrons doesn't take place until all the atomic or molecular orbitals are singly occupied.