Amines, amino acids and polymers

Created by

Tom Prior

Cards (38)

What is an amine?
Organic compounds, derived from ammonia in which one or more hydrogens in ammonia has been replaced by a carbon chain or ring
What is an aliphatic amine?
The nitrogen atom is attached to at least one straight or branched carbon chain, the simplest aliphatic amine with one methyl group attached to the nitrogens
What is an aromatic amine?
The nitrogen atom is attached to an aromatic ring, phenylamine is the simplest aromatic amine
How can amines be classified?
Primary, secondary, tertiary
How many R groups does a primary amine have?
1
How many R groups does a secondary amine have?
2
How many R groups does a tertiary amine have?
3
How to name a primary amine?
Give the amine group the lowest numbering
Find the longest carbon chain
Name it as stem-ethyl (i.e. methylamine)
How to name a secondary amine?
Find the longest carbon chain
Add N to the front of the chain
And name with di,tri and tetra infront of it to determine the number of alkyl groups
How can amines act as bases?
The lone pair of electrons on the nitrogen can accept a proton, when it does this a dative covalent forms between lone pair of electrons on the nitrogen atom and the proton, this will form a positive ion.
What is the salt formation when amines act like bases?
They neutrilise acids to make salts,
e.g. propylamine + Hcl -> propylammonium chloride
How are primary amines formed?
starting: 1-chloropropane, from there NH3 is added and propylammonium chloride (salt),
propylammonium chloride is added to sodium hydroxide to form Propylamine, NaCl and H20
What are the essential conditions for the formation of primary amines?
Ethanol used as the solvent, this prevents substitutions by water to form alcohols
Excess ammonia is used, this reduced further subsitutions of the amine group preventing secondary or tertiary
How are secondary amines formed?
Primary amine + Chloroalkane -> dipropylammonium salt
Salt + NaOH -> Secondary amine
How are tertiary amines made?
The further reactions of secondary amines with chloroalkanes and NaOH
Preparation of aromatic amines?
Reduction of nitrobenzene with tin and Hcl to form the ammonium salt, which is then reacted with excess NaOH
What is an amino acid?
It is a compound which contains both an amine and a carboxylic functional group
What is an Alpha amino acid?
It is an amino acid which has the amine group, next to the carboxyl group
What is the general formula of an Alpha amino acid?
RCH(NH2)COOH
What is odd about amino acids in terms of their reactivity?
They have both an acidic COOH and a basic NH2 functional group, meaning that they will react like an carboxylic acid and an amine group
Reactions of the amine group in amino acids? 
They react with acids to make salts,
e.g. 2-aminopropanoic acid + HCl -> Ammonium Propanoate + Cl-
How does the carboxylic acid group react in amino acids?
It reacts with aqueous alkali to form a salt and water
It also reacts with alcohols (sulfuric acid catalyst) to form esters
What is a zwitterion? 
With the structure of an amino acid the amine can accept a proton from the carboxylic acid group to form an ion which has both a positive and negative charge
What charge do zwitterions have?
They have no overall charge, (+ive and -ive charges cancel eachother out).
What is the isoelectric point?
It is the point at which the pH at which the zwitterions formed cancel eachother out and each amino acid has its own unique isoelectric point
What happens if the pH of the solution the amino acid is in is above/below the isoelectric point?
Above- The amino acid behaves like a base and loses an proton
Below- The amino acid behaves like an acid an accepts a proton
What is an amide?
It is the product of reactions of acyl chlorides with ammonia and amines
What is the difference between primary/secondary/tertiary amides?
primary amide has one carbon atom bonded to the N, secondary amide has two carbon atoms bonded to the N, tertiary has three carbon atoms bonded to the N
What is stereoisomers?
Compounds with the same structural formula but a different arrangement of atoms
What are optical isomers?
They are found in a compound which has a chiral center, this is due to the presence of the chiral center resulting in the existence of non super-imposable mirror image structures, forming optical isomers/enantiomers
What is a chiral center?
It is a carbon atom which is attached to four different atoms or groups of atoms
How can a chiral carbon be labelled?
With an asterisk
How can optical isomers be drawn?
They can be drawn in 3d with a tetrahedral arrangement
What is condensation polymerisation? 
It is the joining of monomers with the loss of a small molecule, this is usually water. In order for this to happen there need to be two differing functional groups
What is is a polyester?
It is the joining together of small monomers in an ester linkage, they form when a carboxylic acid has 2 c=o bonds and an alcohol has 2 OH groups
What are polyamides? 
Condensation polymers formed when monomers are joined together by amide linkages in a long chain to form a polymer. As with polyesters they can be formed with one monomer which has 2 functional groups or 2 monomers with two functional groups.
Which two ways can a condensation polymer be formed by? 
Hot aqueous alkali or hot aqueous acid such as hydrochloric acid
What is the main key difference between products of addition polymers and condensation polymers? 
Addition polymers has a continuous chain of carbon atoms
Where as condensation polymer has either an ester linkage (c=o, c-o) or an amide link (NH2, C=O, c-o)