Question

Inorganic Chemistry/Molecular Theory

a) Fully explain what a centrosymmetric molecule is and why it follows the rule of mutual exclusion.

b) In complete sentences explain why (in regards to a Walsh Diagram) as bonding decreases, energy increases.

Answer 1

a) centrosymmetric molecule is the molecule having inversion as one of the symmtry element i.e. after reflection through the mirror, the molecule should be same as original.

rule of mutual exclusion states that any centrosymmetric molecule cannot have normal modes of vibrations simultaneously for Infra Red and Raman spectroscopy. Due to this reason all centrosymmtric molecules follows the rule of mutual exclusion.

b) Walsh diagrams represent orbital binding energies of a molecule with respect to the bond angles. With increase in energy of any molecular system, there will be decrease in bonding since the minimum energy represents the most stable bonding state. Any change in bonding with respect to bond angles will change stablity of molecule which results into change in energy of the molecule and any such change in bonding is directly influences energy.