Question

Find the number of delta bonding molecular orbital from the following set if z is the internuclear axis:
$$d_{x^2-y^2}$$ and $$d_{xz}$$ , $$d_{x^2-y^2}$$ or $$d_{xz}$$

Answer 1

Hint: In chemistry, the delta bonds are covalent chemical bonds, where four lobes of one involved atomic orbital overlap four lobes of the other involved atomic orbital and form a molecular orbital. This overlap leads to the formation of a bonding molecular orbital with two nodal planes which contain the internuclear axis which is the Z-axis in this case and go through both atoms. So, the lobes of the combining orbitals must necessarily be in the X-Y plane.

Complete answer:
Here, the number of delta bonding molecular orbital from the following set if z is the internuclear axis is 1.
Delta bonding molecular orbital is formed by the overlap of $$d_{x^2-y^2}$$and $$d_{x^2-y^2}$$ orbitals when z is the internuclear axis. If we consider overlapping with $$d_{xz}$$, it won’t be feasible because a successful overlap requires two conditions, which are the combining orbitals should be of the same energy and should have the same orientation in space. The $$d_{xz}$$orbital lies in the X-Y plane intersecting the quarters whereas the orbital has its lobes lying towards X-axis and Y- axis.
So, the correct answer is 1.

Note: Delta bonds are formed by sideways overlap of four lobes of d-orbitals. Delta bonds are weaker than sigma bonds but stronger than pi bonds. For example, there is one delta bond found in the compound $${\left[{\mathrm{Re}}_{2}C{l}_8\right]}^{2-}$$.