Compounds containing Nitrogen Flashcards
Hydrolysis of nitriles/amides
Product, R+C
= Carboxylic acid
> Dilute sulphuric acid
Production of aliphatic amines
Mechanism, R+C, by-product
*Nucleophilic substitution > Halogenoalkane > Excess ammonia > Ethanol solvent = Ammonium salt (NH4X)
Dehydration of an amide
Product, R+C
= Nitrile (-H2O)
> Phosphorus (V) oxide (P4O10)
How would you make an aromatic amine?
R+C
> Nitrobenzene > Steam distillation > Concentrated HCl > Granulated tin > Aqueous sodium hydroxide (to neutralise phenylammonium ions)
Explain the basicity of amines.
The nitrogen atom has a lone pair of electrons, these can act as a base by forming a co-ordinate bond with a hydrogen ion.
Are amines soluble in water?
Only smaller amines are soluble in water due to hydrogen bonding.
Amines with longer hydrocarbon chains are insoluble in water because the chains force their way between the water and amine and break the hydrogen bond.
Describe the boiling points of amines
BP increases with molecular mass, due to increased Van der Waals’ and is increased further by hydrogen bonding
Ethanoylation of primary amines
Mechanism, products
*Nucleophilic addition-elimination
= N-substituted amide + HCl
The amide may react with the HCl produced to give an alkylammonium chloride
Aliphatic amine + nitrous acid ->
Observation, R+C
Aiphatic alcohol + Nitrogen(g) + Water
~ The nitrogen gas is seen as colourless bubbles in the reaction mixture
> Room temp.
Aromatic amine + nitrous acid –>
Below 5°C
Diazonium salt + Water
Aromatic amine + nitrous acid –>
Above 10°C
(Observations)
Phenol + water + N2(g)
~ Black oily product and colourless bubbles of nitrogen gas
Coupling reaction of a diazonium salt
Below 5°C
(Product, R+C)
= Azodye (contains -N=N- chromophore)
> Alkaline solution (aqueous NaOH)
What happens if the diazonium salt is placed in water at room temperature?
Decomposition occurs producing
phenol + N2(g) + HCl
Explain the high melting temperatures of amino acids
They can form zwitterions which are ionic, the strong attractive forces between positive and negative charges requires significantly more energy to overcome.
How many possible dipeptides can be formed if two amino acids are joined together? What type of reaction is occuring?
If the two amino acids are the same then only one dipeptide may be formed. However, if the two amino acids are different then two different dipeptides may be formed.
Condensation reaction
Hydrolysis of poly/dipeptides
Product, R+C
= Constituent amino acids
> 6M HCl
> Reflux/ Strong heat
> Neutralisation using alkali
Describe 1° protein structure
The sequence of amino acids in a chain
Describe 2° protein structure
The amino acid chains coil into pleated sheet or helix due to hydrogen bonding
Describe 3° protein structure
The resulting overall 3D shape produced by electrostatic attraction and disulphide bridges
Name 3 uses of proteins in living systems
- Hair/feathers
- Cartilage
- Enzymes
- Hormones
- Source of energy
- Transport
List two features of addition polymerisation and give an example
- Monomer needs to have a C=C double bond
- No by-product
- Only one starting material
Example : polymerisation of propene to polypropene
Give the reagents and conditions required for the polymerisation of an alkene
> Increased pressures, particularly with gaseous alkene molecules
A radical initiator (starts the reaction and is used up during the process)
List two factors of condensation polymerisation and give the reagents required for the formation of a polyester
- Two molecules join together with the elimination of a small molecule
- The two starting materials need to be bi-functional
Example : Ethane-1,2-diol + benzene-1,4-dicarboxylic acid –> PET
What are the two starting materials required for the formation of Nylon-6,6?
1,6-diaminohexane and hexane-1,6-dioic acid
What are the two starting materials required for the formation of kevlar?
Benzene 1,4-dicarboxylic acid and 1,4-diaminobenzene
