Molecular orbitals of three or more atoms

In summary, Molecular orbital theory states that when two atoms, A and B, are in close proximity, their s atomic orbitals combine to form two molecular orbitals, one bonding and one anti-bonding. This becomes more complex when three or more atoms are involved, as their s atomic orbitals combine to form three molecular orbitals, with differing coefficients and energy levels. These molecular orbitals can be categorized as bonding, non-bonding, or anti-bonding, depending on the overlap of the atomic orbitals. For a linear triatomic molecule, there will be one bonding orbital, one non-bonding orbital, and one anti-bonding orbital. The number of nodes in each orbital also increases with the number of
  • #1
hokhani
483
8
In Molecular orbital theory, when two atoms A & B come close to each other, their atomic orbitals (say their s orbitals) combine and make two molecular orbitals, one bonding and the other anti-bonding. How about molecular orbitals of three or more atoms? For three atoms say A & B & C we would have three molecular orbitals obtained from their s atomic orbitals. Which of them are bonding and which anti-bonding?
 
Physics news on Phys.org
  • #3
For three equal s orbitals in a line with equal distance, there will be three molecular orbitals with coefficients of the atomic orbitals A, B and C equal to (up to overall normalization) (a,b,a), (1,0,-1), and (c,-d,c), where a, b, and c are positive numbers. The first one is bonding (positive overlap between all orbitals), the second one non-bonding (as there is no overlap between neighbouring atoms) and the third one anti-bonding (negative overlap). The first one has no nodes, the second one one node (change from plus to minus) and the third one two nodes. Correspondingly, for four atoms you get one with no nodes, one with one node, one with two nodes and one with three nodes which are consecutively higher in energy.
 
  • #4
Thanks. Could You please introduce me an elementary reference that deals with molecular orbitals without using group theory?
 
Last edited:
  • #5
Look out for "qualitative molecular orbital theory". I can't help you with specific titles.
 
  • Like
Likes 1 person

What are molecular orbitals of three or more atoms?

Molecular orbitals refer to the regions in space where electrons are most likely to be found around a molecule. When three or more atoms come together to form a molecule, their atomic orbitals combine to form molecular orbitals.

How are molecular orbitals of three or more atoms formed?

Molecular orbitals are formed through a process called molecular orbital theory, which combines the wave functions of the individual atoms to create new wave functions for the molecule as a whole. The resulting molecular orbitals have different energies and shapes than the atomic orbitals.

What is the difference between bonding and anti-bonding molecular orbitals?

Bonding molecular orbitals are formed when the wave functions of the individual atoms overlap constructively, resulting in a lower energy state and a stable bond between the atoms. Anti-bonding molecular orbitals, on the other hand, are formed when the wave functions overlap destructively, resulting in a higher energy state and a destabilizing effect on the bond between the atoms.

How do the number of atomic orbitals affect the number of molecular orbitals formed in a molecule?

The number of molecular orbitals formed in a molecule is equal to the number of atomic orbitals that combine to form them. Therefore, a molecule with three atoms will have three molecular orbitals, while a molecule with four atoms will have four molecular orbitals.

Can molecular orbitals of three or more atoms be visualized?

Yes, molecular orbitals can be visualized using computational methods such as molecular orbital diagrams. These diagrams show the energy levels and shapes of the molecular orbitals in a molecule, providing a visual representation of the electron distribution in the molecule.

Similar threads

  • Atomic and Condensed Matter
Replies
1
Views
2K
  • Atomic and Condensed Matter
Replies
8
Views
2K
Replies
3
Views
1K
  • Atomic and Condensed Matter
Replies
4
Views
2K
  • Atomic and Condensed Matter
Replies
0
Views
374
  • Atomic and Condensed Matter
Replies
4
Views
2K
  • Biology and Chemistry Homework Help
Replies
4
Views
2K
  • Atomic and Condensed Matter
Replies
21
Views
2K
  • Atomic and Condensed Matter
Replies
1
Views
1K
Replies
26
Views
1K
Back
Top