Amines Flashcards
What is an Amine?
Derived from ammonia molecules and all contain a nitrogen atom where hydrogens are replaced with an organic group
What are the 3 types of Amines?
Primary – one hydrogen replaced
Secondary – two hydrogen’s replaced
Tertiary Structure – three hydrogen’s replaced
What is formed when there are 4 organic groups?
Quaternary Ammonium salts
What are non aromatic amines also known as?
Aliphatic amines
What are Quaternary Ammonium Salts?
Made up of positive end are attracted to negative ions. Used to make cleaning products such as shampoo, laundry detergents and washing up liquids
What are Cationic Surfactants?
Quaternary Ammonium Salts that have a long hydrocarbon tail; positively charged
How do Cationic Surfactants function?
Non polar tail is attracted to oil/grease. Polar head will be attracted to the water. This now allows the water and oil to mix and remove grease from clothing, skin and dishes. Cationic Surfactants have a positive ammonium ion which is attracted to negatively charged fibres + hair. This removes static so is used in hair conditioner + fabric softener.
How do Amines act as a base?
Amines have a lone pair of electrons that allows them to accept a proton and hence they act as a base
What bond is formed between the proton and amine?
Dative Covalent / Co-ordinate bond
What does the strength of the bond depend on in amines?
The availability of the lone pair of electrons on the nitrogen. The higher the electron density = more readily available electrons are
What is the electron density dependent on in amines?
The type of group attached to the nitrogen
What are the 2 ways of producing aliphatic amines?
- Reacting with halogenoalkane w/ excess ammonia
* Reducing nitrile
What is the downside for reacting with halogenoalkane with excess ammonia?
This produces not only primary amines but also secondary, tertiary and quaternary salts so this produces impure products.
Why are there so many impure products with reacting with halogenoalkane and excess ammonia?
This occurs as primary amines still have a lone pair of electrons on the nitrogen so it acts as a nucleophile, therefore, react with any remaining haloalkanes to prod. a secondary amine, then react further to make tertiary + quaternary salts.
What requirements are needed for the production of aliphatic amines via reducing nitriles?
- Catalyst = Nickel / Platinum
- Hydrogen Has
- High temperature + pressure
