Amine Flashcards
What is the chemical formula for amines?
NH2
What are amines an organic derivative of?
Ammonia (NH3)
How can you classify amines?
- Primary (RHN:H) amine
- Secondary (RRN:H) amine
- Tertiary (RRN:R) amine
- Quarternary (RRN+RR) ammonium salts
What is the nomenclature for aliphatic and aromatic amines?
- alliphatic: -amine
- aromatic: e.g. phenylamine
Describe the physical properties of amines in terms of solubility.
- soluble in organic solvents
- lower mass compounds are soluble in
water due to hydrogen bonding the
solvent - solubility decreases as molecules get
heavier
Are amines acidic or basic?
Basic as they accept protons since they have a lone pair.
RNH2 + H+ -> RNH3+
What happens when amines dissolve in water?
- they produce weak alkaline solutions
CH3NH2(g) + H2O (l) CH3NH3+ (aq)
+ OH- (aq)
What happens when amines react with acids?
- they produce salts
CH3NH2(l) + HCl(aq) -> C6H5NH3+Cl- (aq) + NaCl(aq) + H2O (l)
How can you make aliphatic amines?
- from halogenoalkanes
What are the reagents, conditions and equations for the preparation of aliphatic amines from halogenoalkanes?
- Reagent: ethanolic ammonia
- Condition: heat h-alkane with reag.
2NH3 + CH3CH2Br -> CH3CH2NH2 +NH4Br
What are the steps for making an aromatic amine?
1) tin & conc. HCl under reflux (forms salt)
2) NaOH to convert amine salt into amine
nitrobenzene + 6[H] -> phenylamine + 2H2O
What are azo dyes?
- man made dyes containing the azo group
- N=N-
- having 2 aromatic groups creates a very stable molecule as the azo group becomes part of the delocalised electron system
What is the benefit of having two aromatic groups in azo dyes?
It creates a very stable molecule- the azo group becomes part of the delocalised electron system.
What is the structure of a diazonium ion?
_
benzene- N+= N
What is the structure of a diazonium salt?
benzene - N+ (triple bond)= N Cl-
