IB Chemistry R3.4 Notes

Electron-pair sharing

The last type of reaction you need to know about involves the sharing of electron pairs. During these reactions, two terms frequently come up:

1. Electrophile - this is an electron-deficient reagent with a positive or partially positive charge that accepts electron pairs.
2. Nucleophile - this is an electron-rich reagent with a negative or partially negative charge that donates electron pairs.

These will result in two different types of reactions occurring:

1. An electrophile will accept an electron pair as a part of electrophilic substitution or electrophilic addition.
2. A nucleophile will donate an electron pair as a part of nucleophilic substitution.