What is Orbital Overlap Concept?
Ionic interactions and covalent bonding are viewed as 2 basic concepts for the chemical bond in today's knowledge of the phenomenon. Ionic bonds include the traditional electrostatic interactions between point charges. Electron-sharing or donor-acceptor bonds, which involve two orbitals that are profoundly populated and one that is vacant, are the two most common ways covalent bonding is described.
Even though Pauli's repulsion is greater than the electrostatic repulsive force when the orbital overlap concept increases, both types of bond formations ignore interactions among electrons with the same spin. The involved atom sizes, valence electrons, and degree of orbital overlap are the distinguishing factors. Furthermore, a larger overlap leads to a relatively strong bond formation among the two atoms. Thus, the orbital overlap theory explained the combination of atoms by interfering with one another's orbitals, resulting in relatively low energy levels where valence electrons come together to constitute covalent bonds.
What is the Concept of Orbital Overlap?
An orbital overlap is the combination of orbitals by the collision of neighbouring atoms in the space of the same area, which occurs in chemical bonds leading to a bond formation facilitated by orbital overlap. The two atoms that are close to one another, penetrate each other's orbitals during the orbital process, creating a new hybridised orbital through which the electrons of the bonding pair are located. Because it is less energetic than the atomic orbital, this hybridised orbital is firm and has a low energy state. Thus, the partial fusion of the orbital explains the orbital overlap concept.
To further clarify the system, it should be noted that it takes place over an atomic orbital. An atomic orbital is a location within the atom's interior where there is a high likelihood of finding electrons. The two provided nuclei within the atoms are also drawn to one another by the enhanced electron density in a small area, which reduces their repulsive forces.
For example, a covalent bond between H and Cl is the end outcome of the response.
Orbital Overlap Theory
Chemical bonding and the atom's shape or geometry are governed by how orbitals are arranged, which are explained by the below two orbital overlap theories. Molecular orbital theory (MOT) or Valence Bond Theory (VBT) can both be utilised to describe how these orbitals are arranged. The VBT explains the electron pair's orbital overlap. s, p, and d orbitals make up the majority of atomic orbitals.
The VBT states that a σ bond will be developed when two s or p orbitals overlap head-to-head. A π bond is created when two concurrent p-orbitals overlap. Since a double bond contains both a σ and a π bond; a single bond will comprise a σ bond. The MOT explains how overlapping atomic orbitals create molecular orbitals. This theory states that a molecular orbital can only support a maximum of 2 electrons. To reduce the attraction among them, these charged particles possess opposite spin.
Difference Between VBT and MOT
Overlap of Atomic Orbitals
The atomic orbitals of 2 atoms overlap once they are nearer to one another. The overlapping of atomic orbitals can have positive, negative, or zero overlaps, relying upon these characteristics. The figure beneath shows the different configurations of the s and p-orbitals that lead to positive, negative, and zero overlaps.
Positive atomic orbital overlap: Whenever the two involved atomic orbitals phase is identical, positive overlap takes place. Bonds are created as a consequence of this overlap.
Negative atomic orbital overlap: Negative overlap occurs whenever the phases of the involved atomic orbitals oppose one another. Bond formation doesn't take place in this instance.
Zero overlaps of atomic orbital: Zero atomic orbital overlaps occur while two intriguing orbitals do not overlap with each other in an orbital.
The orbital overlap diagram is shown below.
Structure of Orbital Overlap
Orbital Overlap in Cumulene Compounds
The existence of 2 main carbon atoms carrying 2 double bonds accounts for the orbital overlap in cumulene compounds' rigidity. Due to the sp hybridisation of such carbon atoms, 2 π bonds—one to near each carbon atom—are formed. Cumulene molecules thus possess linear geometry. Hybridisation of cumulene contains 9 (σ) and 2 (π) bonds.
Key Features of Orbital Overlap
The phrase "atomic orbital overlap" is another name for orbital overlapping.
Linus Pauling highlighted the significance of orbital overlap while characterising the molecular bond angles found during experimentation.
The idea of orbital hybridisation also represents an additional development of orbital overlapping.
Orbital overlap refers to the methodology whereby a partial merger of orbitals creates a completely novel hybridised orbital. The overlapping regions of the orbitals are called pi (π) and sigma (σ).
Bond-forming orbitals must have the same orientation and mode in space.
The pair of atoms involved, their size, and valence electrons all play a role in determining the degree of overlap level. Higher levels of overlap result in the atoms forming firmer bonds with one another.
Conclusion
So, bond chemistry helps analyse the orbital overlap that happens when two atoms mingle with molecules. With the help of bond chemistry, orbital overlap theories VBT and MOT explain the atomic orbital overlap, while VBT specifically explains the orbital hybridisation concept where MOT falls short.
FAQs on Orbital Overlap: A Detailed Summary
1. What Results in Orbital Overlap?
The reasons why orbital overlap occurs is the sense that they occupy space in some form or the other. Since atoms take up space, the resultant reaction leads to atomic orbitals overlap. Now, to further explain the process, the entire process happens over an atomic orbital. An atomic orbital is a place inside the space of atoms where the possibility of detecting electrons is very high. Further, in a confined space, the two given nuclei inside the atoms are attracted by the increased electron density, and their repulsions are decreased. The final results of the reaction of which is a covalent bond between H and Cl.
2. What are the Orbital Phases? Explain Hybridisation?
To begin with, orbitals are the essential mathematical functions that help us develop and define all the intricate patterns that hover around standing waves, that can be easily graphed over a graph. However, it should be noted that these orbitals don’t have a physical reality. An orbital process is the result of the action between electrons’ wave-like properties.
On the other hand, orbital hybridisation (or hybridisation) is the chemical process that helps in combining of atomic orbitals to form new hybrid orbitals (combined efforts of different energies, sizes, etc., then atomic orbitals) suitable for pairing electrons in valence bond theory to form chemical bonds.
3. Where can students find useful information regarding the Orbital Overlap?
Students can find everything they need on the Vedantu app or website. These study materials are created by professionals and the content is accurate and reliable. These study materials are completely free and there is no cost at all. All students just have to sign in and then they will be able to download what you want in pdf format. Students can find information on concepts like Orbital Overlap, bond formation, types of bonds, and a whole lot more!
4. What is Orbital Overlap?
In chemical bonds, an orbital overlap can be defined as the merging of orbitals on adjacent atoms in the same regions of space. Orbital overlap can lead to bond formation. During the orbital process, when two atoms come nearby then they penetrate each other’s orbital forming a new hybridized orbital in which the bonding pair of electrons reside. This hybridized orbital is stable since it has lower energy than the atomic orbital. It is in the minimum energy state. This partial penetration of the orbital to form a new hybridized orbital is known as orbital overlap.
5. What is Positive Overlapping of Atomic Orbital?
If any two atoms come in contact with each other then they form a bond, the bond can be positive, negative or even zero and that totally depends on the phase and sign of the two interacting orbitals.
Positive Overlapping of Atomic Orbital – When the two interacting atomic orbitals are in the same phase, then the overlap is positive and this leads to bond formation. The phase of the two interacting orbitals (+ or -) depends on the sign of orbital wave function and is not related to the charge in any way.
6. What do you mean by zero overlapping of Atomic Orbital?
If any two atoms come in contact with each other then they form a bond, the bond can be positive, negative or even zero and that totally depends on the phase and sign of the two interacting orbitals.
Zero Overlapping of Atomic Orbital - When two orbitals with different phases interact with each other, there is no overlapping of the orbitals. A zero overlap results in orbitals that are not overlapping at all or not overlapping efficiently. A zero overlap occurs between orbitals that do not result in the forming of bonds.
7. What are Orbital phases?
The phase of an orbital or the Orbital phase is a direct consequence of the wave-like properties of the electrons. In the graphical representation of orbitals, the phase of the orbital is decided from a plus or minus sign (having no relationship to electric charge in any way) or by colouring/shading one lobe. The sign of the phase does not have physical meaning to itself. They are useful when mixing orbitals to form molecular orbitals.
8. How do orbital phases work?
The connection among orbitals that results from their wave property is referred to as the orbital phase. Also, it must be recorded that these orbitals do not possess an external fact.
W9.hat causes orbital overlap?
Orbital overlapping occurs due to the space-occupying nature of atoms.
10. What type of atomic orbitals overlap?
Sigma (σ) and pi (π) are overlapping orbitals. They both are developed by the overlapping of two orbitals with one. The internuclear axis, further referred to as the orbital overlapping among the nuclei of atoms, is where sigma bonds are formed.
11. What happens when electron orbitals overlap?
Orbital overlapping takes place when electron orbitals get closer to each other. This process minimises the energy potential since the positive-negative electrostatic forces within the nuclei of one atom and 2nd electron are now feasible. The bands are eventually established as a result of this.
