“The resonance effect is defined as ‘the polarity produced in the molecule by the interaction of two π-bonds or between a π-bond and lone pair of electrons present on an adjacent atom’. ”
This effect is transmitted through the chain.
There are two types of resonance designated as R effect.
Two types of R Effect
+R effect or positive resonance effect: “The transfer of electrons in this effect is away from an atom or substituent group that is connected to the conjugated system.
+R effect shown by aniline as follows:-
-R effect or resonance effect:" This effect is observed when the transfer of electrons is towards the atom or substituent group attached to the conjugated system."