amines

amine natural product

quinine

shape

nitrogen has 3 single bonds and adopts a pyramidal shape

bond angles of 107

4 sp3 hybrid orbitals are formed

1 sp3 is doubly occupied

valence bond model for bonding in amines

overlap of sp3 hybrids

doubly occupied sp3 hybrid not involved in bonding

lone pair is high energy

reactivity in amines

bonding is an extension of ammonia

amines are electron-rich and are nucleophiles

polarity and physical properties

C-N bonds are weakly polarised

N-H bonds are highly polarised

small amines are relatively soluble in water due to hydrogen bonds

amines are basic, nucleophilic and oxidisable

readily react with acids and with oxidising agents - lone pair on N

Bronstead basicity

amines react readily with electron poor species - if this is a H+ it is a bronstead base

when a nucleophile reacts with an acid we say it is a base

product is ammonium salt

Lewis basicity of amines

a full orbital from one atom overlaps with an empty orbital from another atom, creating a new orbital

identical to a covalent bond - coordinate or dative

amines and drugs

most amine drugs are administered in the form hydrochlorides or related compounds

nucleophilicity of amines

amines can be the nucleophile using the lone pair