Question

Shifting of electrons of multiple bonds under the influence of a reagent is called__________.

• A. inductive effect
• B. mesomeric effect
• C. electromeric effect
• D. none of the above

Answer 1

Answer: (C)

electromeric effect

Electromeric effect refers to a molecular polarizability effect occurring by an intramolecular electron displacement (sometimes called the conjugative mechanism and, previously, the tautomeric mechanism) characterized by the substitution of one electron pair for another within the same atomic octet of electrons.

This effect is shown by those compounds containing multiple bonds. When a double or a triple bond is exposed to an attack by a reagent, a pair of bonding electrons involved in the $\pi$ bond is transferred completely from one atom to another.

This effect will remain as long as the attacking reagent is present. As soon as the reagent is removed, the polarized molecule will come back to the original state.

Option C is correct.