Amines Flashcards
What are amines classed as?
Primary, secondary or tertiary.
How are amines classed?
Depending on how many hydrogen atoms have been replaced by organic groups compared to ammonia (NH3).
What is the bond angle on an an amine and why?
107, because of the lone pair of electrons.
Do amines act as acids or bases?
Both
How do amines act as bases?
The lone pair of electrons on the Nitrogen can attract hydrogen ions, or accept a proton.
What do amines acting as bases produce?
Ionic salts
What is the order of base strength from strongest to weakest?
Secondary amine, primary amine, ammonia and aryl amine.
Why are aryl amines weaker bases than ammonia?
The lone pair of electrons are delocalised onto the aromatic ring.
What is the inductive effect?
Alkyl groups release electrons making the lone pair more available for donation.
How is the inductive effect shown?
An arrow along the bond in the direction of electron release.
Why can amines and ammonia act as nucleophiles?
The lone pair of electrons on the nitrogen atom with which they can attack compounds with a C^d+.
What is the reaction of ammonia with a halogenoalkane? What are the conditions?
Nucleophilic substitution. Ethanol with excess ammonia.
What is the product of the reaction of ammonia with a halogenoalkane?
A primary amine (also a nucleophile)
What would be produced if there was excess halogenoalkane in a reaction of ammonia with the halogenoalkane?
A primary amine would form, then a secondary amine, then a tertiary amine and eventually a quarternary ammonium salt.
What is the reaction in which amines react with acid chlorides and acid anhydrides?
Addition-elimination
What is produced in the reaction between an amine and an acid anhydride/acyl chloride?
Amides.
How can primary amines be prepared?
The reduction of nitriles with hydrogen and a nickle catalyst.
How can phenyl amines be prepared?
By nitrating the arene with with conc. H2SO4 and nitric acid and then reducing the nitro-compound with tin and HCl.
What is a condensation polymer?
A polymer produced from two different monomers with two functional groups- eliminates a small molecule (H2O).
What are polyesters made from?
A diol and a dicoarboxylic acid.
What are polyamides made from?
A diamine and a dicarboxylic acid.
How can condensation polymers be broken down?
Hydrolysis
Why are the hydrogen bonds not as strong in amines as in alcohols?
Oxygen is more electronegative and so there is stronger dipole-dipole attraction in an -OH group.
Why are primary amines soluble in water and alcohols?
They form hydrogen bonds with these solvents.
Why are tertiary akylamines not stronger bases than secondary akylamines?
They are less soluble in water
Name 4 uses of amines.
- Nylon,
- Polyurethane,
- Dyes,
- Drugs.
What ammonium compound is used in the manufacture of hair and fabric conditioners and why?
Quarternary ammonium compounds (cationic surfactants) because they form cations.
How do ammonium compounds act as hair and fabric conditioners?
Hair and wet fabric pick up negative charges. Positive charges on cations attract them to the wet surface and form a coating that prevents build up of static.
How do you name an amide?
N- (carbon atoms attached to N) (carbon atoms attached to =O) amide
What condition would you use to produce a primary amine in the nucleophilic substitution of a halogenoalkane by ammonia?
Excess ammonia
What condition would you use to produce a secondary or tertiary amine in the nucleophilic substitution of a halogenoalkane by ammonia?
Excess halogenoalkane.
