Class Functional group/name Suffix Examples Formula

alkane C - C ane ethane CnH2n+2

alkene C = C Alkenyl ene ethene CnH2n

alkyne C ≡ C Alkynyl yne ethyne CnH2n-2

alcohol O-H Hydroxyl ol ethanol CnH2n+1OH

ether C – O - C Ether oxyalkane methoxymethane R –O -R

ketone O ‖ C – C - C

Carbonyl one propanone CnH2nO

or R-CO-R

aldehyde C = O ׀ H

Aldehyde anal ethanal CnH2nO

or R -CHO

Carboxylic acid O ‖ C – O H

Carboxyl oic acid ethanoic acid CnH2n+1COOH

ester O ‖ C – O –C

Ester oate ethyl ethanoate R – COO-R

amide CONH2 Amide anamide propanamide

amine NH2 Amine amine ethanamine

nitrile C ≡ N Nitrile nitrile propanenitrile

halogenoalkane F, Br, CI, I Halogeno chloroethane R - CI

Functional group

H H H H

׀ ׀ ׀ ׀

H - C – C – C – C – O-H

׀ ׀ ׀ ׀

H H H H

Hydrocarbon skeleton Functional gp

IUPAC nomenclature Systematic naming organic molecules

H CI O ‖ ׀ ׀

H - C – C – C - OH

׀ ׀ H H C1 – functional gp

C2 – substituent gp - CI

2 – chloropropanoic acid

Prefix Stem Suffix

Position and

substituent

Longest carbon

chain

Functional

gp

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3 2 1

H CH3 H H H

׀ ׀ ׀ ׀ ׀

H - C - C – C – C – C – H

׀ ׀ ׀ ׀ ׀

H H H H H

H H H H

׀ ׀ ׀ ׀

H - C – C – C – C – O-H

׀ ׀ ׀ ׀

H H H H

Hydrocarbon skeleton Functional gp

Hydrocarbon

Aliphatic Aromatic

Saturated Unsaturated

benzene alkylbenzene

H H

׀ ׀

H - C – C – H

׀ ׀

H H

H H

׀ ׀

C = C

׀ ׀

H H

Alkane Cycloalkane

Compound Ethane Ethanoic acid

Empirical formula CH3 CH2O

Molecular formula C2H6 C2H4O2

Full SF

Condensed SF CH3CH3 CH3COOH

Stereochemical formula

(3D)

H H

׀ ׀

H - C – C – H

׀ ׀

H H

H O

‖ ׀

H - C - C - OH

׀

H

Organic Chemistry

Cycloalkene Alkene

IUPAC nomenclature

Ring form

Functional group

Structural formula

2 – chloropropanoic acid

no aromatic ring

Systematic naming organic molecules

Prefix Stem Suffix

Position and

substituent

Longest carbon

chain

Functional

gp

H CI O ‖ ׀ ׀

H - C – C – C - OH

׀ ׀ H H C1 – functional gp

C2 – substituent gp - CI

CH3(CH2)3CH3

H H H H H

׀ ׀ ׀ ׀ ׀

H - C - C – C – C – C – H

׀ ׀ ׀ ׀ ׀

H H H H H

Use of parenthesis

Repeat CH2 x 3

CH3CH(CH3)(CH2)2CH3

Repeat CH2 x 2 CH3 branch

H CH3 H CH3 H

׀ ׀ ׀ ׀ ׀

H - C - C – C – C – C – H

׀ ׀ ׀ ׀ ׀

H H H H H

CH3CH(CH3)CH2CH(CH3)CH3

CH3 branch

3 2 1

benzene ring

inside

Isomerism Molecules with same molecular formula but diff arrangement of atom

Two types of Isomerism

Positional Chain Isomer Functional Gp Isomer

C – C – C – C – OH

C4H10O1

Structural Isomerism

• Same molecular formula • Diff structural formula • Diff arrangement of atom

Diff hydrocarbon chain skeleton

• Same molecular formula • Same structural formula • Diff spatial arrangement of atom

Stereoisomerism

Hydrocarbon Chain Isomer

Diff functional gp position Diff functional gp

C – C – C – OH

׀

CH3

C – C – C –C

׀

OH

C – C – C – C

׀

OH

C – C – C – C

׀

OH

C – C – C – O – C

Optical Isomer Geometric Isomer

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Compound Ethane Ethanoic acid

Empirical formula CH3 CH2O

Molecular formula C2H6 C2H4O2

Full SF

Condensed SF CH3CH3 CH3COOH

Stereochemical formula

(3D)

Isomer Physical property

Chemical property

Structural isomer - Hydrocarbon chain - Functional gp position - Functional gp

Different Different Different

Similar Similar

Different

Geometrical isomer Different Similar

Optical isomer Similar Similar

H H

׀ ׀

H - C – C – H

׀ ׀

H H

H O

‖ ׀

H - C - C - OH

׀

H

Structural formula – arrangement atoms in molecule (2/3D)

H H

׀ ׀

H - C – C – H

׀ ׀

H H

CH3CH3

ethane

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Diff functional gp position

C4H9OH

Structural Isomerism

• Same molecular formula • Diff structural formula

• Diff arrangement of atom

Diff hydrocarbon chain skeleton

Diff functional gp position

Diff functional gp

CH3-CH2-CH2-CH3 ׀

OH

Butan–1-ol

CH3-CH-CH2-OH ׀

CH3

2-Methylpropan-1-ol

CH3 ׀

CH3-C-OH

׀

CH3

CH3-CH2-CH-CH3 ׀

OH

2-Methylpropan-2-ol Butan-2-ol

CH3-CH2-CH2-O-CH3

Methoxypropane

CH3-CH2-O-CH2-CH3

Ethoxyethane

7 structural isomers

CH3-CH-O-CH3

׀

CH3

CH3-CH2-CH2=CH2

C4H8

CH3-CH=CH-CH3 CH3-C=CH2

׀

CH3

CH2 – CH2

׀ ׀ CH2 - CH2

C4H9Br

CH3-CH2-CH2-CH2

׀

Br

CH3-CH2-CH-CH3

׀

Br

CH3 ׀

CH3-C-Br

׀

CH3

CH3- CH-CH2

׀ ׀

CH3 Br

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C6H14

CH3-CH2-CH2-CH2-CH2-CH3 CH3-CH-CH2-CH2-CH3

׀

CH3

CH3-CH2-CH-CH2-CH3

׀

CH3

CH3

׀

CH3-C-CH2-CH3

׀

CH3

CH3- CH- CH-CH3

׀ ׀

CH3 CH3

Diff hydrocarbon chain skeleton

Diff functional gp position

Diff functional gp Diff hydrocarbon

chain skeleton

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4 structural isomers 4 structural isomers

5 structural isomers

Diff hydrocarbon chain skeleton

Structural Isomerism

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C3H6O

H

׀

CH3-CH2-C=O

O

‖

CH3-C-CH3

OH

׀

CH3-CH=C-H

OH

׀

CH2=CH-CH2 CH3-O-CH=CH2

C4H8O

CH3-CH2-CH2-C-H ‖

O

CH3 -CH2 -C-CH3

‖

O

CH3-CH - C-H ‖ ׀

CH3 O

CH2=CH-CH2-CH2-OH CH3-CH=CH-CH2-OH CH3-CH2-CH=CH-OH CH3-CH2-O-CH=CH2 CH3-CH=CH-O-CH3

C5H10

CH2=CH-CH2-CH2-CH3 CH3-CH=CH-CH2-CH3 CH2=C-CH2-CH3

׀

CH3

CH2=CH-CH-CH3

׀ CH3

CH3-CH=C-CH3

׀

CH3

CH2-CH-CH2-CH3

CH2

CH3-CH-CH-CH3

CH2

CH3

׀

CH2– C-CH3

CH2

CH2

CH2 CH2 ּו

׀ ׀ CH2 –CH2

CH2 –CH-CH3

׀ ׀

CH2– CH2

Aldehyde Ketone Alkene/Alcohol Alkene/Alcohol Alkene/Ether

5 structural isomers

8 structural isomers

10 structural isomers

Cyclo – ring structure

• Same molecular formula • Diff structural formula

• Diff arrangement of atom

C5H11Br

Structural Isomerism

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CH3-CH2-CH2-CH2-CH2-Br CH3-CH2-CH2-CH-CH3

׀

Br

CH3-CH2-CH-CH2-CH3

׀

Br

CH3-CH-CH2-CH2-Br

׀

CH3

CH3-CH2-CH-CH2-Br

׀

CH3

CH3

׀

CH3–CH–CH-CH3

׀ Br

CH3

׀

CH3-CH2- C-CH3

׀ Br

CH3

׀

CH3-C-CH2-Br

׀ CH3

CH3- CH- CH-Br

׀ ׀

CH3 CH3

CH3 CH3

׀ ׀

CH3- C - CH2

׀ Br

CH3

׀

CH3-CH2- C-Br

׀ CH3

C3H6O2

CH3-CH2-C-OH

‖

O

CH3 - C- O-CH3

‖

O

H- C-O-CH2-CH3

‖

O

CH2- CH = CH

׀ ׀

OH OH

CH=C-CH3

Ι Ι

OH OH

HO-C=CH-CH3

׀

OH

HO-CH-CH=CH2

׀

OH

OH

׀

CH3-CH–C-H

‖

O

CH2- C = CH2

׀ ׀

OH OH

OH

׀

CH2-CH2-CH

‖

O

CH3-O-CH2-CH

‖

O

CH2 = C-O-CH3

׀

OH

CH2= CH-O-CH2

׀

OH

CH=CH-O-CH3

׀

OH

2-bromo-3-methylbutane 2-bromo-2-methylbutane

8 structural isomers

Alcohol / Alkene

Carboxylic acid Ester Aldehyde / Alcohol

Alcohol / Alkene / Ether

14 structural isomers

• Same molecular formula • Diff structural formula

• Diff arrangement of atom

H H H H H

׀ ׀ ׀ ׀ ׀

H - C – C – C - C – C – F

׀ ׀ ׀ ׀ ׀

H CH3 H H H

H CH3 ׀ ׀

CI – C – C – C

׀ ׀

H CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – Br

׀ ׀ ׀

H CH3 H

H CH3 H H

׀ ׀ ׀ ׀

H - C – C – C - C – H

׀ ׀ ׀ ׀

I H H H

H C

׀ ׀

C – C – C – C - C

׀

CI

C CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

CI H H

CH3 ׀

CI – C – C – C

׀

H

H H CI

׀ ׀ ׀

H - C – C - C – H

׀ ׀ ׀

H CH3 H

Halogenoalkane and Nomenclature

H

׀

CH3 – C – CI

׀

H

Types of halogenoalkane

Primary 1 0

NO alkyl /1 alkyl/R gp bond to C attach to halogen

H CH3 H

׀ ׀ ׀

H - C – C – C – CI

׀ ׀ ׀

H CH3 H

H

׀

H - C – CI

׀

H

Secondary 2 0

2 alkyl/R gp bond to C attach to halogen

H

׀

CH3 – C – CI

׀

CH3

H H H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H CI H

H

׀

R – C – CI

׀

R

Tertiary 3 0

3 alkyl/R gp bond to C attach to halogen

CH3

׀

CH3 – C – CI

׀

CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H CI H

R

׀

R – C – CI

׀

R

H H H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H CI H

H CH3 H

׀ ׀ ׀

H - C – C – C – C

׀ ׀ ׀

H CI H

CH3

׀

CH3 – C – CI

׀

CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H Br H

C ׀

CI – C – C – C

׀

C – C

Br CH3

׀ ׀

C – C – C – C – C

׀ ׀

CH3 CH3

C CI C

׀ ׀ ׀

C – C – C – C – C

׀

C

Primary 1 o

Secondary 2 o

Tertiary 3 o

H H H

׀ ׀ ׀

H - C – C - C – H

׀ ׀ ׀

H H F

H H CH3 H H

׀ ׀ ׀ ׀ ׀

H – C – C - C – C – C - H

׀ ׀ ׀ ׀ ׀

H CI CH3 H H

H

׀

CH3 – C – CI

׀

CH3

C ׀

HO – C – C – C

׀

C – C

H CH3 ׀ ׀

HO – C – C – C

׀ ׀

H CH3

H H H H H

׀ ׀ ׀ ׀ ׀

H - C – C – C - C – C – OH

׀ ׀ ׀ ׀ ׀

H CH3 H H H

H CH3 H

׀ ׀ ׀

H - C – C – C – OH

׀ ׀ ׀

H CH3 H

H CH3 H H

׀ ׀ ׀ ׀

H - C – C – C - C – H

׀ ׀ ׀ ׀

OH H H H

H C

׀ ׀

C – C – C – C - C

׀

OH

C CH3

׀ ׀

H - C – C – C – H

׀ ׀ ׀

OH H H

CH3 ׀

HO – C – C – C

׀

H

H H OH

׀ ׀ ׀

H - C – C - C – H

׀ ׀ ׀

H CH3 H

Alcohol and Nomenclature

H

׀

CH3 – C – OH

׀

H

Types of alcohol

Primary 1 0

NO alkyl /1 alkyl/R gp bond to C attach to OH

H CH3 H

׀ ׀ ׀

H - C – C – C – OH

׀ ׀ ׀

H CH3 H

H

׀

H - C – OH

׀

H

Secondary 2 0

2 alkyl/R gp bond to C attach to OH

H

׀

CH3 – C – OH

׀

CH3

H H H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H OH H

H

׀

R – C – OH

׀

R

Tertiary 3 0

3 alkyl/R gp bond to C attach to OH

CH3

׀

CH3 – C – OH

׀

CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H OH H

R

׀

R – C – OH

׀

R

H H H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H OH H

H CH3 H

׀ ׀ ׀

H - C – C – C – C

׀ ׀ ׀

H OH H

CH3

׀

CH3 – C – OH

׀

CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H OH H

OH CH3

׀ ׀

C – C – C – C – C

׀ ׀

CH3 CH3

C OH C

׀ ׀ ׀

C – C – C – C – C

׀

C

Primary 1 o

Secondary 2 o

Tertiary 3 o

H H H

׀ ׀ ׀

H - C – C - C – H

׀ ׀ ׀

H H OH

H H CH3 H H

׀ ׀ ׀ ׀ ׀

H – C – C - C – C – C - H

׀ ׀ ׀ ׀ ׀

H OH CH3 H H

H

׀

CH3 – C – OH

׀

CH3

H H H H H

׀ ׀ ׀ ׀ ׀

H - C – C – C - C – C –NH2

׀ ׀ ׀ ׀ ׀

H CH3 H H H

H CH3 ׀ ׀

NH2 – C – C – C

׀ ׀

H CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – NH2

׀ ׀ ׀

H CH3 H

H CH3 H H

׀ ׀ ׀ ׀

H - C – C – C - C – H

׀ ׀ ׀ ׀

NH2 H H H

H C

׀ ׀

C – C – C – C - C

׀

NH2

C CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

NH2 H H

C ׀

NH2 – C – C – C

׀

H

H H NH2

׀ ׀ ׀

H - C – C - C – H

׀ ׀ ׀

H CH3 H

Amines and Nomenclature

H

׀

CH3 – C – NH2

׀

H

Types of amines

Primary 1 0

NO alkyl /1 alkyl/R gp bond to C attach to nitrogen

H CH3 H

׀ ׀ ׀

H - C – C – C – NH2

׀ ׀ ׀

H CH3 H

H

׀

H - C – NH2

׀

H

Secondary 2 0

2 alkyl/R gp bond to C attach to nitrogen

H

׀

CH3 – C – NH2

׀

CH3

H H H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H NH2 H

H

׀

R – C – NH2

׀

R

Tertiary 3 0

3 alkyl/R gp bond to C attach to nitrogen

CH3

׀

CH3 – C – NH2

׀

CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H NH2 H

R

׀

R – C – NH2

׀

R

H H H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H NH2 H

H CH3 H

׀ ׀ ׀

H - C – C – C – C

׀ ׀ ׀

H NH2 H

CH3

׀

CH3 – C – NH2

׀

CH3

H CH3 H

׀ ׀ ׀

H - C – C – C – H

׀ ׀ ׀

H NH2 H

C ׀

NH2 – C – C – C

׀

C – C

NH2 CH3

׀ ׀

C – C – C – C – C

׀ ׀

CH3 CH3

C NH2 C

׀ ׀ ׀

C – C – C – C – C

׀

C

Primary 1 o

Secondary 2 o

Tertiary 3 o

H H H

׀ ׀ ׀

H - C – C - C – H

׀ ׀ ׀

H H NH2

H H CH3 H H

׀ ׀ ׀ ׀ ׀

H – C – C - C – C – C - H

׀ ׀ ׀ ׀ ׀

H NH2 CH3 H H

H

׀

CH3 – C – NH2

׀

CH3

Delocalization of electrons

Resonance • Describing delocalization of electrons within a molecule/polyatomic ion where bonding cannot be express by ONE single Lewis structure • Delocalization of π bond – π electrons spread over more than 2 nuclei • π electrons are shared/spread – more stable

Resonance structures benzene

Benzene 6HC6

resonance structure 1 resonance structure 2

Resonance hybrid

• All bonds C6H6 are identical in length/ strength • Hybrid of 2 resonance structures • No C-C (single) or C=C (double) bonds found • Only C ----- C bond • Intermediate character bet single/double bond

• Bond Order =

• Unhybridised p orbital • Delocalization electrons above below plane • sp2 hybridization on carbon center

1.5

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Delocalized electrons

Kekulé structure

Cyclohexa- 1,3,5 triene

χ ✓ double/single bonds bet them

Benzene

Hexagonal, planar

Resonance Hybrid more stable than any of the resonance structure ✓

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Kekule

✓

or

Resonance/Delocalization Energy

ΔH cyclohexene = -120 kJmol-1

ΔH cyclohexa1,3,5 triene = - 360 kJmol-1

ΔH Benzene = - 208kJmol-1

Enthalpy change hydrogenation

χ

- Benzene lower in energy by 152 kJ - More stable due to delocalization of π electrons

- 152 kJ

- 152

C-C Single bond

C = C Double bond

C = C Benzene

Bond length/pm 154 134 140

Bond enthalpy/kJmol-1

346 614 507

Evidence for Benzene structure

1

2

Click here evidence against Kekule

• X ray hit benzene crystal • Interact with electron (electron density map) • X ray diffraction produced • Bond length measured

X ray crystallography

NO single/double bond detected ✓

✓

3 No addition rxn in benzene C=C

Addition rxn

Substitution rxn

NO double bond

-240

……

-360

- 208

ΔH cyclohexa 1,3 diene = -240 kJmol-1

+

✓

✓

+ Br - Br → ✓