13.8 Amines Flashcards
What are Amines?
Relatives of ammonia (NH3)
What do alkyl groups in amines do?
In amines, one or more of the hydrogen atoms on the ammonia molecule are replaced by alkyl chains
What are amines with one alkyl group called?
What are amines with two alkyl groups called?
What are amines with three alkyl groups called?
Primary Amine
Secondary Amine
Tertiary Amine
Do the alkyl groups in secondary and tertiary amines need to be identical?
No, for example CH2NCH3CH3 is trimethylamine
How are Amines named?
The alkyl groups are arranged in alphabetical order, and placed in front of the suffix amine.
Sometimes the amines can be named using “amino” to represent a NH2 group, for example 2-amino-pentane:
What are Amines with two amino groups called?
Amines with two amino groups attached are called diamines
What are the physical characteristics of Amines?
The amines with low molecular masses are gases, or volatile liquids. The volatile amines resemble ammonia in having strong “fishy smells”.
What is the significance of the lone pair on the Nitrogen Atom?
The lone pair of electrons on the nitrogen atom is responsible for many of the amines characteristics.
The lone pair is similarly found in ammonia; the reactions of the amines closely resemble the reactions involving ammonia.
- Very soluble in water
- A Base
- A ligand
- A nucleophile
Why are Amines more soluble in water and what increases its solubility?
Amines with small alkyl groups are very soluble in water. This is because hydrogen bonding occurs between the amine and water molecules.
The larger the alkyl chain and the more of them there are, the less soluble the amine is in water.
What kind of bonding can the lone pair take part in?
Dative Bonding.
How do Amines work as Bases?
The electron pair can be donated to an H+ ion; the amine can act as an H+ acceptor, and thus can act as a base.
What do amines dissolve in water to form?
Like ammonia, amines dissolve in water to form an alkaline solution. This is due to the formation of hydroxide ions
Why are Amines effective ligand?
They have a lone pair electrons on the N atom can bond to metal ions.
Why can Ammonia act as nucleophiles?
The lone pair on the nitrogen atom.
What is a nucleophile?
Nucleophiles are substances that can “attack” a positively charged carbon atom by donating a pair of electrons.
