Amines Flashcards
How do you amines ?
-amine
Or
Amino-
Why are amines so reactive ?
The lone pair of electrons on the nitrogen - due to the polar N-H bond
What shape are amines around the N and what is the bond angle ?
Trigonometry pyramidal, 107º due to lone pain on N
What kind of intermolecular forces do they have and why ?
Hydrogen bonding due to the polar N-H bond and lone pair of electrons on the N atom
How are amines produced ?
- when one or more of the hydrogen atoms in ammonia is replaced by another group
- can be primary, secondary or tertiary
What mechanism is involved in the production of amines ? And what is the product?
Amines are produced from the reaction of a halogenoalkanes with ammonia
- nucleophilic substitution
- produces a primary amine and ammonium salt
What are primary amines ?
- have a general formula of RNH2
- R can be an alkyl or aryl group
- amines are named using the suffix -amine, for example methyl amine
What are secondary amines ?
- have the general formula RR’NH.
What are tertiary amines ?
- general formula - RR’R’‘N
- eg trimethlyamine
- different R groups are put in alphabetical order
Do amines have intermolecular forces which are stronger than or weaker than alcohols?
- weaker, as N has lower electronegativity than O therefore has weaker hydrogen bonding
What state are amines at 298K ?
Short chains are gases, longer chains are volatile liquids
What do amines smell like and why ?
- fishy rotten meat
- releases di and triamines
Which primary amines are soluble in water/alcohols ?
- up to 4 carbon atoms, as they can hydrogen bond to water molecules
- after this the non-polarity of hydrocarbons chain makes them insoluble
Is phenylamine soluble ?
- no not very soluble, due to the non-polarity of the benzene ring
When can amines act as bases ?
When they bond with H+ ion