Functional group
Types
Hydrocarbons
Alkanes
C-C
C-H
Alkenes
C=C
Aliphatic (CnH2n+2)
Cycloalkanes (CnH2n)
Saturation
Saturated
Unsaturated
Polarity
Non-polar C-H bonds
Non-polar C-H, C-C,
C=C bonds
Alkyl groups are e
donating, may cause
polarity due geometric
isomerism
Boiling/melting point
Melting point is 'irregular'
due to packing (Even C
atom alkanes pack more
closely, more attraction)
Solubility
Acidity
Soluble in non-polar
solvents
Insoluble in water (highly
polar solvents)
Can dissolve low polarity
compounds as solvent
Cis-isomers: groups on
same side, overall dipole
moment, pd-pd
interactions)
*remember alkyl groups
are e donating
Exception: cisbutenedioic acid has
lower bp (-COOH are
close to form
intramolecular H bonds
rather than inter)
Soluble in non-polar
solvents
Insoluble in water (highly
polar solvents)
*slighly polar cis-isomer
is still hydrophobic
Arenes
Benzene ring
*very stable due to
resonance, delocalised pi
bond
2-, 4- directing [A]: alkyl
(weak), -NH2, -OH
(strong)
1-, 3- directing [D]: NR3+,
-NO2 (strong)
Halogens (w) are [D] but
are 2-, 4- directing.
Acts 'saturated' but is
unsaturated
Non-polar
Halogen Derivatives
R-X
Ar-X
Primary (1) SN2
Secondary (2)
Tertiary (3)SN1
Hydroxyl Compounds
Alcohols
R-OH
Phenols
Ar-OH
Ketones
C=O flanked by adjacent
R/Ar groups
Alphatic
Aromatic
Primary (1)
Secondary (2)
Tertiary (3)
Halogenoarenes (directly
attached)
Either
Either
Either
Polar
Negative charge on -X
Soluble in non-polar
solvents
Insoluble in water (denser
and sinks)
Unsaturated
Unsaturated
Polar
Negative charge on =O
Increases with increasing C atoms
(Mr increases, e cloud size increases, more id-id interactions)
Decreases with increasing branching
(Molecule becomes more spherical, less SA for id-id interactions)
Bp higher than
Bp higher than
Bp higher than most
corresponding alkanes
corresponding alkanes
organic compounds due
with similar no. of C
with similar no. of C
to H-bonding
(Polar bond, more pd-pd
(formation of H bonds
If intra H-bonding occurs,
interactions, higher bp)
between OH)
lower bp because less
intermolecular H-bonding
Soluble in non-polar
solvents
Insoluble in water (highly
polar solvents)
Excellent solvent (but
carcinogenic, may lead to
leukemia)
Carbonyl Compounds
Aldehydes
C=O on terminal
compound
Soluble in non-polar
solvents (can still form idid interactions with R
groups)
Soluble in water (-OH is
hydrophilic)
*decreasing solubility as
C increase as id-id
become predominant
between R-group, intefere
with H bonding with
water and –OH)
Very weak acid
*weaker than acid
*alkoxide ion is very
unstable (e donating R
group intensifies charge
on O=, more ready to
accept protons,
equilibirium lies to the
left)
*more R, more intensified
the negative charge is,
more unstable, lower
acidity
*only react with strong
acids/reactive metals
Soluble in non-polar
solvents
Insoluble in water
(Hydrophobic benzene
ring)
Weak acid, but stronger
than water and alcohol
*phenoxide stabilised as
negative charge is
dispersed over ring via
resonance
*partial double bond of
C-O to form delocalised
cloud (Delocalisation of
negative charge,
resonance stabilised)
*e withdrawing group
will increase strength
(reduce intensity of
negative charge on O)
Bp higher than corresponding alkanes with similar no.
of C (Polarbond, more pd-pd interactions, higher bp)
Soluble in non-polar solvents (can still form id-id
interactions with R groups)
Soluble in water (lone pair on O forms H bonding)
*decreasing solubility as C increase as id-id become
predominant between R-group, intefere with H bonding
with water and –O)
Excellent solvent
Reactions/Reactivity
Preparation
Unaffected by polar
reagents
(Non-polar: no centre to
electrical charge to attract
charged species,
Saturated: no region of
high/low electrondensity
to attract
electro/nucleophiles)
[EA]
Reduction of alkenes [H2
(g) + Ni + heat, H2 (g) +
Pt/Pd]
Dehydration of alcohols
[excess conc H2SO4 +
170C, Al2O3 + 400,
H3PO4 + 200-250C]
[ES] to maintain
aromaticity
Dehydrohalogenation of
halogenoalkanes
[KOH/NaOH, ethanol,
heat]
*Staytzeff's Rule (more R
groups, more stable)
*trans-isomer more stable
Combustion [O]
Complete
Non-sooty flame (Bigger
H:C ratio when saturated)
Sooty flame (Smaller H:C
ratio)
[NS] SN2/ SN1
[E] Elmination
*Dehydrohalogenation
*contains susceptible
beta-proton lost during
elimination
*beta proton situated on C
adjacent to C-X
*in alocoholic medium:
strong base
*bond strength of C-X
*Saytzeff's rule
*trans-isomer is stabler
[ES] for halogenoarenes
*less reactive toward
[NS]
*partial double bond
character: p-orbital of X
overlaps with pi-e cloud
of benzene ring,
delocalisation of e
*e rich benzene repels
electrons of nucleophile
[FRS] of alkanes
[Br2/Cl2 + heat/UV]
[ES] of alkanes
Formation of dihalide
[X2 in CCl4 + dark]
Formation of
halogenoalkane
[HX]
Substitution in alcohols
* main source
[HCl + heat + anhydrous
ZnCl2/NaBr + heat +
conc. H2SO4 (forms
HBr)/NaI + H3PO4 (forms
HI)]
[PX3 (produced in
situ)/PCl5/SOCl2 (reaction
with SOCl2 is cleaner due
to formation of gases that
can escape)]
[Acid-metal reaction]
[C]
[A]
[NS] (because of O)
[NA] C has partial positive charge due to polar bond
Aldehyde reacts faster
*less steric hindrance (only 1 R group vs 2 R groups)
*more e deficient to attract nucleophiles (2 R groups in
ketones donate more e, partial positive charge less
intenese, less susceptible to attack)
Aromatic less reactive
*less susceptible to nucleophilic attack as C is less e
deficient due to interaction of pi-electron cloud of
carbonyl group and bezene ring
*steric hindrance of bulky benzene ring on aooriaching
nucleophile
[ES]
[EA] of alkenes
[1. Cold conc. sulfuric
acid 2. water +
heat/industrial:
phosphoric acid on celite
+ 300C + 70 atm]
[NS] of halogenoalkanes
[NaOH/KOH (aq) + heat]
[R] of carboxylic acids
[LiAlH4 in dry ether]
[R] of aldehydes/ketones
[LiAlH4 in dry ether,
NaBH4, H2 + Ni catalyst
+ heat]
Pale blue (non-luminous)
Produces CO2 (g) and H2O (l)
General formula: CxHy + (x + 0.25y) O2 → x CO2 + 0.5y H2O
Exothermic, can be used as fuel.
Alkanes found in natural gas, hydrocarbons found in crude oil.
Hydrocarbons separated into fractions by fractional distillation.
(refinery gas, light petroleum, light naphtha, gasoline/petrol, kerosene/paraffin, gas
oil, lubrication oil, paraffin wax, bitumen/asphalt)
Petrol: mixture of C5 – C10 alkanes
Premature explosions for unbranched alkanes causes knocking
Causes wear and tear within enginge as wastes petrol
To reduce:
Use petrol with high octane number
Add tetraethyl lead (anti-knock agent): weak Pb-C bonds easily broken ensures
smooth combustion, but produces PbO which coats on engine. 1,2-dibromoethane
added to react to form PbBr2 gas (Adds Pb to air which causes brain damage when
inhaled)
[ES] (because of benzene
ring)
-OH is 2,4 directing
[O] of primary alcohols
[K2Cr2O7 (aq)/MnO2 (aq)
+ H2SO4 (aq) + heat with
immediate distillation]
[O] of secondary alcohols
[K2Cr2O7 (aq)/KMnO4
(aq) + H2SO4 (aq) + heat]
[O] if alkenes
[KMnO4 (aq) + heat]
Incomplete
Br2 (l) in CCl4
-
Heat/UV
Br/Cl2 (with
FeX3/AlX3)
-
Friedel-Crafts
Alkylation
(CH3Cl, AlCl3)
Br2 (aq)
Produces CO2 (g) and H2O (l) AND CO (g) and C (s)
Causes pollution*
Yellow (luminous)
Forms dihalide [EA]
Decolourisation of brown
Br2 (in the dark to
differentiate from FRS)
Heterolytic fission of Br2,
Br+ attacks C=C,
formation of carbocation
[slow], attacked by Br= to
form product [fast]
*only 1 product
Forms halogenoalkane
[FRS]
Decolourisation of
brown/yellow-green
Br2/Cl2
Litmus: Blue to Red
(HBr/HCl fumes)
Forms halogenoarene
[ES]
*monosubstituted product
Decolourisation of brown
Br2
[FRS] of side chain of
methylbenzene
Decolourisation of
brown/yellow-green
Br2/Cl2
Litmus: Blue to Red
(HBr/HCl fumes)
Forms halogenated
benzene [ES]
*halogen carriers to
active halogens
*excess may form 1,4dichlorobenzene
Decolourisation of
brown/yellow-green
Br2/Cl2 gas
Litmus: Blue to Red
(HBr/HCl fumes)
1. Generation of
electrophile Cl+ (Cl2 +
AlCl3 → Cl+ + [AlCl4]-)
2. Cl+ attacks benzene to
form benzonium ion
[slow]
3. [Cl3Al-Cl]- removes H
to restore aromaticity
[fast]
Forms mono-nitratedmethybenzene [ES]
Same as above
BUT may form more than
one due to 2,4 directing
White fumes of HCl
*methylbenzene is mor
reactive, further
alkylation will occur
1. Generation of
electrophile +CH3 (CH3Cl
+ AlCl3 → +CH3 + [AlCl4])
2. +CH3 attacks benzene
to form benzonium ion
[slow]
3. [Cl3Al-Cl]- removes H
to restore aromaticity
[fast]
Forms halohydrin [EA]
Decolourisation of brown
Br2
Same as Br2 in CCl4, but
excess of H2O gives
higher chance of
[ES] of halogenoarene
Forms halogenoarene
[ES]
*trisubstituted product
(ionises partially to form
pheonixide which is more
e-rich and undergoes ES
carbocation reacting with
H2O (with lone pair on O
acting carbocation,
acquires positive charge
removed by heterolytic
fission of O-H)
*stability of carbocation
AgNO3 (aq)
H2O (l)
HBr (g)/ HCl (g)/HI (g)
PCl5/PCl3/SOCl2/PBr3
more eaily)
Decolourisation of brown
Br2
Formation of white ppt
(2, 4, 5-triboromophenol)
Room
temperature
With
anhydrous
ZnCl2 catalyst
Generated
from NaBr
with
concentrated
H2SO4, heat
Generated
from KI with
concentrated
H3PO4 , heat
-
2,4dinitrophenylhydrazine
Fehling's solution
-
Tollen's reagent
Warm
I2 with NaOH (aq)
Warm
Forms halogenoalkane
[EA]
Polar HBr with Hδ+
attacking C=C, formation
of 2 carbocations [slow],
attacked by Br= to form
product [fast]
Stable carbocation formed
faster (Less positive
charge, more stable)
R groups are e donating,
diminish positive charge,
more stable
Halogens are e
withdrawing, intensify
charge, less table
*Markovnkikov's Rule
Forms halogenoalkane
[NS]
Forms halogenoalkane
[NS]
With -Clx, steamy white
fumes of HCl produced
Warm
[O]
*test for carbonyl groups
*forms orange prcipitate when present
*test for aldehyde and not
ketone
forms carboxylate salt [O]
*contains copper (II)
compllex which is
reduced to Cu2O, reddish
brown ppt
*only for aliphatic
aldehydes
*test for aldehyde and not
ketone
forms carboxylic acid [O]
*Silver Mirror test
*silver mirror present
when aldehyde is present
*contains aq.
Diaminesilver(I) ions
[O]
*test for alcohol with a
methyl group and H
attached to –COH
Yellow crystals are
formed
RC(HOH)CH3 + 4I2
6NaOH → RCOO-Na+ +
CHI3 + 5NaI + 5H2O
HCN (with trace of
NaOH/KCN)
Cold
Dilute acids
Heat
Concentrated H2SO4
industrial:
phosphoric
acid on celite +
300°C + 70
atm
(addition of
water while
heating in step
2)
170C
Concentrated HNO3
(with Concentrated
H2SO4)
60C
60C
*test for carbonyls with a methyl group attached to C=O
*
Forms cyanohydrins [EA]
Nucleophile: -CN (C less EN, will donate e more than
N)
*HCN dissociates in water to form ions (N very EN,
draws e towards self, chain reaction, H is very e
deficient and extracted to form weak acid)
*rate=k[ethanal][CN-]
*increase [CN-] by adding NaOH/KOH (base reacts
with H+ causing [H=] to fall and equilibrium shifts to
produce more H+ and CN- or add strong electrolyte
containing CN- like NaCN or KCN (complete ionisation
provides sufficient CN-, not used directly because HCN
is needed as proton donor for mechanism/H 2O can also
be deprotonated by HO bond is much stronger than HC
bond)
CN attacks C with partial positive charge to form
anionic intermediate [slow], anionic intermediate is
protonated to form final cyanohydrin product [fast]
Acid hydrolysis of nitrile
to carboxylic acid
*N replaced by –OOH
*NH4+ is a product too
Acid hydrolysis of cyanohydrin to carboxylic acid
*N replaced by –OOH
*NH4+ is a product too
Forms alcohols [EA]
H on H2SO4 attacks C=C
to form carbocation
[slow], negative O with
lone pair (with H
removed from it) attacts
carbocation to form
intermediate
Addition of water to form
alcohol to to 'complete'
H2SO4
Forms alkenes [E]
*saytzeff's rule
*trans-isomer more stable
Forms mono-nitrated
benzene [ES]
1. Generation of
electrophile NO2+
(HNO3 + 2H2SO4 →
2HSO4- + NO2+ + H3O+)
2. O=N+=O attacks
benzene ring, formation
of benzonium ion with H
and NO2 attached to an
sp3 C [slow]
3. basic HSO4= removes
H from sp3 C to restore
aromaticity, regeneration
of sulfuric acid
*rememeber to write
down sp2/3 C
*arrows are important
[ES] of halogenoarene
[fast]
Forms mono/di/trinitrated-methybenzene
[ES]
Same as above
BUT may form more than
one due to 2,4 directing
Increasing nitration needs
harsher conditions
di-: 90C, reflux
tri-: fuming conc. acids
30C
Concentrated HNO3
-
Neutral FeCl3 (aq)
-
Concentrated KMnO4
with H2SO4 (aq) or
Concentrated KMnO4
with H2SO4 (aq)
(acidified after heating)
Heat
Dilute KMnO4 with
NaOH (aq)
Cold
K2Cr2O7/Na2Cr2O7 with
H2SO4 (aq)
Heat (If
KMnO4 is
used)
Forms trisubstituted
phenol [ES] (conc.)
Forms monosubstitued
phenol [ES] (dilute)
*2 possible products
*test for phenol
Violet complex forms
[O]
*complete cleavage of pi
bond
Decolourisation of purple
KMnO4
No R: CO2 + H2O
Formation of gas which
forms white ppt with
limewater
1R: Carboxylic acid
[O] of sidechain of
methylbenzene
*tertiary alkyl side chains
not oxidised
*will always form
benzoic acid
Forms carboxylic acid
[O]
2R: Ketone
Formation of diol [O]
Decolourisation of purple
KMnO4 and formation of
brown ppt MnO2
*pi bond cleaved 2 form 2
new sigma bonds
1: Forms carboxylic acid
2: Forms ketone
Purple solution
decolourises
Orange solution turns
green
1: Forms aldehyde
Orange solution turns
green
Heat with
immediate
distillation
(1) O3 (2) Zn(s), H2O
(l), heat
Ozonolysis [O]
*complete cleavage of pi
bond
Zinc to remove H2O2
formed
No/1R: Aldehyde
2R: Ketone
Na (s)
-
NaOH (aq)
Room
temperature
Heat
[Acid-metal reaction]
H2 gas evolves gives a
'pop' sound with alighted
splint
Forms alcohols [NS]
Nucleophile: OH*hydrolysis has little
effect as H2O is a weak
nucleophile
[Acid-metal reaction]
H2 gas evolves gives a
'pop' sound with alighted
splint
[Acid-metal reaction]
Dissolves to give
colourless solution
Alkaline hydrolysis of cyanohydrin to carboxylate salt
*N replaced by -OO*NH3 is a product too
Alkaline hydrolysis of
nitrile to carboxylate salt
*N replaced by -OO*NH3 is a product too
Na2CO3/NaHCO3
NaOH in ethanol
Heat
NH3
Dissolved in
ethanol, heat in
sealed tube
KCN/NaCN in ethanol
Heat
LiAlH4 in dry ether
-
Sn with concentrated
HCl
NaBH4
H2 with Ni catalyst
Heat
High
temperature
and pressure
Willaimson Synthesis
Na in ethanol
NaOH (aq)
350C, 150
atm
Esterification
Carboxylic
acid + alcohol
+ conc.
sulfuric acid +
heat
Forms alkenes [E]
*X-, H+ removed.
*H combines with OH- to
form H2O
Forms amines [NS]
Nucleophile: NH3
*only SN2
1. normal thing goes on,
+
NH3 attached Br= leaves
2. OH- medium takes H
away, left with NH2
*excess NH3: product
formed is more reactive
as R group is electron
donating, enhancing –ve
charge on N, product will
want to react with RX,
increasing R groups,
increasing strength of
nucleophile
Forms nitrile [NS]
Nucleophile: CN*mixed solvent of waterethanol for improved
miscibility
*used to extend carbon
chain
[R] of nitrile to primary
amine
*N replaced by -H2NH2
[R] of cyanohydrin to primary amine
*N replaced by -H2NH2
Forms primary alcohols
Forms secondary alcohols
[R]
[R]
*addition of water and
*addition of water and
heat in second step
heat in second step
Forms alkane [R]
Diffusion, Adsorption,
Reaction, Desorption,
Diffusion
Forms ether [NS]
Nucleophile: OR=
Forms phenol
[hydrolysis]
*Na+ goes replaces Cl*H+ replaces Na+
*difficult due to strong
CX bond
Forms ester [C]
*condenses H2O
*slow and reversible,
lower yield
*Conc. sulfuric acid
(catalyse reaction, remove
water produced to shift
position of equilibrium to
right and increase yield)
Acylation
Carbonyl + compound
with -NH2 group
Anhydrous
acyl group +
alcohol
Forms ester [A]
*condenses HCl (if acid
chloride is used)
*Fast and complete and
yield
Forms ester [A]
*condenses HCl (if acid
chloride is used)
Steamy white fumes of
HCl
*addition of NaOH will
form phenoxide which is
a stronger nucleophile for
faster reaction
[C]
Reaction with NH2-R: forms imine
Reaction with NH2-OH: forms oxime
Reaction with NH2- NH2: forms hydrazine
o
Poisonous when inhaled, lead to brain damage
in young children
FREE RADICAL SUBSTITUTION

Use of catalytic converters
o
Honeycomb structure: Increase SA
o
Coated with Pt/Pd, Rh: Catalyse reaction
o
Remove CO, NOx and unburnt hydrocarbons
o
2NO + 2CO → CO2 + N2 (Rh)
o
CxHy + (x + 0.25y) O2 → x CO2 + 0.5y H2O
(Pt/Pd)
o
2CO + O2 → 2CO2 (Pt/Pd)
o
2x CO + 2NOx → 2xCO2 + N2
o
CxHy + (2x +0.5y) NO → xCO2 + 0.5y H2O
+ (x+0.25y) N2
o
Cars with catalytic converters must run on
unleaded petrol as lead poisions the
catalyst (preferentially adsorbed on
catalyst surface)
Overall reaction: CH4 + Cl2 → CH3Cl + HCl

When there is excess Cl2, further substitution can occur to
give multi-substituted products.

ELECTROPHILIC ADDITION OF BR2
Limit Cl2 or use excess alkane to 'ensure' monosubstitution

UV/light gives energy for homolytic fission to give radicals
for iniation
POLLUTION PROBLEMS

Production of pollutants during incomplete combustion
(IC)/high temperature of internal combustion engine (HT)

CO (IC)
o
Combines with haemoglobin in blood, unable tro
transport O2
o
ELETROPHILIC SUBSTITUTION
(MONO-NITRATION OF BENZENE)
Affect mental alertness, 10% in air, fatal in 2
minutes

Unburnt hydrocarbons and carbon particulates (IC)
o
Mixture of nitrogenous oxides and unburnt
hydrocarbons forms photochemical smog which
irritates the respiratory system and causes lung
damage

Adjustment of fuel:air proportion and engine design and
use of catalystic converters to finish combustion reaction

Nitrogenous oxides
o
Formation of acid rain which corrodes buildings,
destroy land and marine life by increasing
acidity
o
Contributes to photochemical smog
o
NO is a radical which reacts with ozone, causing
ozone depletion and increased surface UV
radiation

Use of catalytic converters to reduce to nitrogen

CO2
o
Greenhouse gas that contributes to enhanced
INDUCTIVE/RESOSNANCE EFFECT
greenhouse effect, leading to global warming,
melting of polar ice caps, rising sea levels and

Inductive: sigma bond

Resonance: pi bond
damage to numerous ecosystems

SO2
o

Contributes to acid rain
Pb compounds
o
o
Diminishes with distance
More pronounced than inductive
NUCLEOPHILIC SUBSTITUTION (SN2)

Antiseptics (2,4,6-trichlorophenol)

DDT (pesticide)

Anaesthetic (CF3CHBrCl)
NUCLEOPHILIC ADDITION

One step only

Rate = k[Nu=][RX]

Dotted and straight lines switch in position, groups still
attached

Nu- attacks from opposite side (backside attack):
o
Stearic hindrance of large X
o
Repulsion due to 2 negative species

Transition state

Walden inversion: conversion from enantiomer to the
other, chiral centre inverted

Factors affecting rate:
o
Weak C-X bond, easier to break, faster reaction
o
Stearic hindrance, presence of R groups block
approach
o
Less R group, faster because more R groups will
donate electrons and makes the positive charge
of C less positive, less susceptible to
nulceophilic attack

1 halogenoalkanes
NUCLEOPHILIC SUBSTITUTION (SN1)

2 steps

rate = k[RX]

C-X breaks hetrolytically to form carbocation (trigonal
planar

Nu- can attack from both sides

2 products in equal proportion

Very fast due to attraction of opposite charges (Nu- and
positive carbocation)

Factors affecting rate:
o
Weak C-X bond, easier to break, faster reaction
o
Stable carbocation, faster
USES OF HALOGEN DERIVATIVES

Refrigerants (CCl2F2)

Aerosal propellants

Fire extinguisher (CBr2ClF)

Grease solvents (dicholoromethane)

Polymer production (chloroethene for PVC)

Petrol additive (1,2-dibromomethane)

Tetraethyllead production (tetraethyllead as anti-knock
agent in petrol)