Chapter 27 - Amines, amino acids and polymers Flashcards
What are amines?
Organic compounds derived from ammonia
What are aliphatic amines?
The nitrogen is attached to at least one carbon chain
What are aromatic amines?
The nitrogen is attached to a benzene ring
What is a primary amine?
One hydrogen, two R groups
What is a secondary amine?
Two hydrogens, one R hroup
What is a tertiary amine?
Three R groups
How do you name a primary amine where the amine group is on carbon 1?
Add the suffix -amine onto the name of the alkyl chain
How to name a primary amine where the amine group isn’t on carbon 1?
Use the prefix amino- and a number to indicate the position on the chain
How do you name secondary or tertiary amines?
The prefixes di- or tri- are used to indicate the number of alkyl groups attached to the nitrogen atom
How do you name amines where two or more compounds are attached to the nitrogen atom?
It is a N substituted derivative of the larger group
What happens when an amine reacts as a base?
The lone pair of electrons on the nitrogen accepts a proton and a dative covalent bond is formed
What is produced when an amine reacts with acids?
A salt is produced
How do you make a primary amine?
A molecule of ammonia acts as a nucleophile in a reaction with a haloalkane
An alkali reacts with the ammonium salt to form the amine
What are the essential conditions needed to make a primary amine?
Ethanol is used as the solvent and excess ammonia is used
How do you make a secondary amine?
You react the primary amine with a haloalkane again so further substitution occurs
An ammonium salt is produced
How do you make aromatic amines?
Heat nitrobenzene under reflux with tin and hydrochloric acid
The ammonium salt is reacted with excess NaOH
General formula of an alpha amino acid
RCH(NH2)COOH
What happens when an amino acid reacts with an acid?
The amine group reacts and a salt is produced
What happens when an amino acid reacts with an alkali?
The carboxylic acid group reacts to form a salt and water
What happens when amino acids are esterified?
Reacted with alcohol
Concentrated sulphuric acid catalyst
Carboxylic acid group is esterified and amine group is protonated
What are amides?
Acyl chloride reacts with ammonia or amine
Which type of molecules will show optical isomerism?
Those with a chiral centre
What is another word for optical isomers?
Enantiomers
Why do amino acids show optical isomerism?
They have a chiral centre
What is a chiral centre?
A carbon atom bonded to four different atoms/groups
What are optical isomers?
Non-superimposable mirror images
How do you draw optical isomers?
Use the three types of line to draw them in 3D either sides of a ‘mirror’
What are the two condensation polymers we study?
Polyesters and polyamides
What is produced during condensation polymerisation?
Monomers upon and lose a molecule of water
What is needed for condensation polymerisation?
Two different functional groups
How are polyesters formed?
Monomers are joined
How are polyesters made from one monomer?
The monomer contains both a carboxylic acid group and an alcohol group
An ester bond forms and a molecule of water is lost
How are polyesters made from two monomers?
One monomer is a diol
One monomers is a dicarboxylic acid
A hydroxyl group reacts with a carboxyl group to form an ester link and water
What are polyamides?
Condensation polymers formed by amide bonds between monomers
What are the two ways in which a polyamide can be formed?
One monomer with a carboxylic and amine group
Two monomers with two of each of these groups
How are polyamides formed from one monomer?
A condensation reaction occurs between the amine group and the carboxyl group to form an ester link and release water
How are polyamides formed from two functional groups?
An ester bond forms between the amine group and the carboxyl group, releasing water
Conditions for hydrolysing polymers
Hot aqueous alkali or hot aqueous acid
For acid and alkali hydrolysis, book is the best
For acid and alkali hydrolysis, book is the best
