University of Lincoln presentation
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

• Contain double or triple bonds, but do not show the same reactivity as other unsaturated hydrocarbons
• Benzene: C
6
H
6
• Used mainly as solvents
H
H
• Substitution rather than
Addition is favoured H
H
H
H
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

H
H
Delocalisation, Resonance:
Stabilise molecules, so make them less reactive
6 p-orbitals
H
H
H
H
H
H
H
H
Delocalised orbital clouds
Three sp2 hybrid orbitals arrange themselves as far apart as possible
-which is at 120° on a plane. The remaining p orbital is at right angles to them.
Each carbon atom uses the sp2 hybrids to form σ -bonds with two other carbons and one hydrogen atom.
Delocalised or Conjugated System:
π-bonding electrons can move within the molecule
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

F
CH
3 CH
3
NH
2
Flurobenzene
Cl
Cl
-ortho
Ethylbenzene
O
OH
Toluene
OH
Aniline
Cl
-meta
1,2-Dichlorobenzene
Cl
-para
Benzoic acid
H
2
C
Phenol
Cl
1,3-Dichlorobenzene
O
O
-
N
+
CH
3
O
N
+
O
CH
3
CH
3
Cl
1,4-Dichlorobenzene o -Xylene
Br m -Bromostyrene
O
-
N
+
O
2,4,6-Trinitrotoluene (TNT)
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

Substitution
O
• Aromatic Substitution reaction – Aromatic compound loses a hydrogen atom and another atom or group takes its place.
+ HNO
3
H
2
SO
4
Cl
Cl
2
AlCl
3
N
+
O
-
Br
2
FeBr
3
+ H
2
O
Br
• It is possible for substitution to occur in more than one place on the ring.
O
N
+
O
-
O
N
+
O
otha -Dinitrobenzene
O
N
+
O
-
N
+
O
O
meta -Dinitrobenzene
O
N
+
O
-
O
-
N
+
O para -Dinitrobenzene
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

• –OH group (hydroxyl group)
• Replace e with ol
• CH
3
OH, methanol, simplest alcohols are classified as primary (1°), secondary
(2°), or tertiary (3°) depending on the number of carbon atoms bonded to the carbon bearing the -
OH group
OH OH
OH
H
3
C H
H
Primary
Alcohol (1 o )
H CH
3
CH
3
Secondary
Alcohol (2 o )
H
3
C CH
3
CH
3
Tertiary
Alcohol (3 o )
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

H
3
C ethanol
OH
H
3
C OH methanol
OH
H
3
C CH
3
2-propanol or propan-2-ol or isopropyl alcohol
OH
H
3
C propanol
H
3
C CH
3
OH
2-ethyl-1-butanol or 2-ethyl-butan-
1-ol
Polyhydroxy alcohols are alcohols that possess more than one hydroxyl group
H O OH
H O
OH
1,2-Ethanediol
(ethylene glycol)
CH
3
H O
OH
1,2-propanediol
(propylene glycol)
H O
1,2,3-propanetriol
(glycerol)
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

■ Reaction with acids to produce Esters
O
HCl or H
2
SO
4
(H
+
Catalyst)
CH
3
H
3
C
H
3
C
+
OH
O O
OH
Acetic Acid
(ethanoic acid)
CH
3
Ethyl acetate
+
■ Redox reaction (Reduction and oxidation)
O O
H
3
C
Ethanol
OH
Oxidation
H
3
C H
Acetaldehyde
Oxidation
H
2
O
H
3
C OH
Acetic Acid
Reduction
H
3
C CH
3
Alcohol Dehydrogenase
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

• –O- group (ether group)
• CH
3
OCH
3
, dimethyl ether simplest
• Soluble in water- H-bonding to water - Polar
• Flammable – Ether can cause flash fires
• Low Reactivity – Make Good
Reaction Solvents
• Naming: alkyl groups in alphabetical order followed by ether
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

• Both contain a carbonyl group (C=O)
R H
O
Aldehyde Ketone
R R
O
Naming
Aldehydes Change -e ending to –al ethane ethanal
(acetaldehyde)
H
H
3
C
Ketones Change -e ending to –one propane propanone
(acetone) H
3
C
O
O
CH
3
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

Synthesis: produced by oxidation of alcohol
OH OH
H
3
C
H
Primary
Alcohol
H H CH
3
CH
3
Secondary
Alcohol
H
3
C
OH
CH
3
CH
3
Tertiary
Alcohol
O O
H
3
C CH
3
H CH
3
Reduction of carbonyl group to produce alcohols
Cannot be oxidised
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

H H
3
C
O O
H
3
C H
3
C
H O
H C
O
H
H O
O +
H
3
C
H O
O
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

• Contains C=O and –OH group on same carbon
• Change -
to -
• Acetic acid: acid in vinegar
• Simplest: methanoic acid
(formic acid)
O O O
H O
H
Methanoic acid
H O CH
3
Ethanoic acid
CH
3
H O
Propanoic acid
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

■ Esterification reactions
O
H
3
C
OH
Acetic Acid
(ethanoic acid)
+
H
3
C
HCl or H
2
SO
4
(H
+
Catalyst)
CH
3
OH
O O
Ethyl acetate
CH
3
+ H
2
O
■ Reduction to aldehydes
H
O
Oxidation
CH
3
Reduction
H O
O
CH
3
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

• Derived from carboxylic acids and alcohols
• Tend to be fragrant
– Methyl butyrate
– Ethyl butyrate apple pineapple
• An ester name has two parts - the part that comes from the acid (propanoate) and the part that shows the alkyl group (methyl).
Example: Methyl propanoate
O
H
3
C CH
3
O
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

Substitution
R
O
O
R
1
R 2 OH
R +
H
2
O
R
2
NH base
Reduction of esters
R
O
R
O
O
R
2
Ester
R
O
O
H
Acid
NH
R
2
Amide
LiAlH
4
+
O
R
1
R
2
H
H
OH
R
1
+ R
2
OH
R
Hydrolisis of esters (basic)
O
+
NaOH
O R
1
Carboxylate ester
Sodium hydroxide saponification or hydrolysis
O
R
O
-
Na
+
Sodium
Carboxylate
+ H O R
1
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License
Alcohol

• Derived from ammonia by substituting H for alkyl groups. It is an alkali
• We have primary, secondary or tertiary amines depending on the number of H substituted
N
N N N
H
H
H
Ammonia
R
H
H
Primary amine (1 o )
R
H
R
1
Secondary amine (2 o )
R
R
2
R
1
Tertiary amine (3 o )
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

NH
2
H
2
N
1,4-butanediamine
Putrescine (found in decaying meat) (1 o )
NH
2
CH
3
Amphetamine
(dangerous stimulant) (1 o )
H
3
C CH
3
N
H
Piperidine
H
3
C
N
CH
3
CH
3
Triethylamine (3 o )
H
2
N NH
2
1,5-pentanediamine
Cadaverine (found in the putrefaction of cadavers
NH
2
Isopropylamine (1 o )
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

Alkylation
R X
+
2 R
1
NH
2
R
R
1
N H + R
1
H
N
+
H
H Na
+
Oxidation reduction
O
N
+
O
-
NH
2
Reduction
Oxidation
Phenylamine
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License

• JISC
• HEA
• Centre for Educational Research and Development
• School of natural and applied sciences
• School of Journalism
• SirenFM
• http://tango.freedesktop.org
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 2.0 UK: England & Wales License