CHEM 2OA3 Lecture Notes - Leaving Group, Nucleophile, Bond Length
19 Mar 2013
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Document Summary
Nucleophile is something that is electron-rich (and thus is attracted to the nucleus: lewis base, attacks something that is bare of electrons, nucleophile will attack another nucleus to kick out a leaving group. The c-x bond is polarized (more electron density around the halogen x than around the carbon) Can"t kick off a hydrogen from ch4 because it would result in a single hydrogen with 2 electrons (hydride), which is extremely high energy, so that would never happen: leaving group will be a halogen. Fluoride is very electronegative, so makes very strong bonds, so it is rarely a leaving group (hard to break it off) As you make a longer chain, bond strength increases (higher boiling point) When h is attacked, we call the attacker a base, but when c is attacked, we call the attacker a nucleophile: nucleophiles are usually negatively charged (electron-rich) Alkyl halides are good starting materials to make alcohols, ethers, and nitriles.
