Electronic transitions in organic molecules involve the transition of electrons from one energy level to another within the molecule. Specifically, these transitions typically involve the movement of electrons in π (pi), σ (sigma), and n (non-bonding) orbitals. These transitions are:

1. σ → σ* Transitions: Transitions from a sigma bonding orbital to a sigma antibonding orbital. These are high-energy transitions.
2. n → σ* Transitions: Transitions from a non-bonding orbital (containing lone pair electrons) to a sigma antibonding orbital.
3. π → π* Transitions: Transitions from a pi bonding orbital to a pi antibonding orbital. These transitions are common in molecules with double or triple bonds.
4. n → π* Transitions: Transitions from a non-bonding orbital to a pi antibonding orbital. These transitions occur in molecules containing both lone pairs and pi systems.

The energy required for these transitions falls within the ultraviolet (UV) and visible regions of the electromagnetic spectrum, making UV-Vis spectroscopy a useful technique for studying these electronic transitions.