This document provides an overview of the IUPAC naming system and structural isomerism. It discusses the key components of IUPAC names, including root words, suffixes, and prefixes. Examples are given to illustrate how names are derived according to IUPAC rules. Additionally, the document defines the five main types of structural isomerism: chain, position, functional group, metamerism, and tautomerism. Specific examples are used to differentiate between each type of isomerism.

1. IUPACNAMING
SYSTEM
& STRUCTURAL
ISOMERISM
MADE BY ~ ABHISEK TEWARI
ROLL NO ~ 12401920002
1ST YEAR 2ND SEM
PAGE 1

2. C
O
N
T
E
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SLIDE 1 – COVER PAGE
SLIDE 2 – CONTENTS
SLIDE 3 – INTRODUCTION TO IUPAC
SLIDE 4 – ROOT WORDS
SLIDE 5 – SUFFIX + PRIMARY SUFFIX
SLIDE 6 - SECONDARY SUFFIX + PREFIX
SLIDE 7 –EXAMPLES OF IUPAC NAMING
SLIDE 8 – STRUCTURAL ISOMERS

3. PAGE 3
 WHAT IS IUPAC
 IUPAC ( IT IS PRONOUNCED AS EYE-YOU-PACK )
[ INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY ]
The IUPAC nomenclature system is a set of logical rules devised and used to write a
unique name for every distinct compound. According to the IUPAC system of
nomenclature, the name of an organic compound consists of a root word, a suffix
and a prefix.
 FEATURES OF IUPAC SYSTEM
 A given compound can be assigned only one name.
 This system is helpful in naming the complex organic compounds.
 This system is helpful in naming the multifunctional groups.
 This is a simple , systematic and scientific method for the nomenclature of
organic compounds

4.  ROOT WORD
PAGE 4
 C
 C - C
 C - C - C
 C - C - C- C
 C - C- C- C - C
 C - C - C - C- C - C
 C - C - C - C - C - C -C
 C - C - C - C - C - C - C -
C
 C - C - C - C - C - C - C -
C - C
 C - C - C - C - C - C - C -
METH
ETH
PROP
BUTE
PENT
HEX
HEPT
OCT
NON
DEC
Number of carbon atoms Root Word

5.  SUFFIX
PAGE 5
A suffix designate the functional groups that may be present in the
compound. The suffix is again divided into primary and secondary.
 PRIMARY SUFFIX
 Primary suffix is added immediately after the root word.
 Primary suffix + Root word → Saturated or unsaturated carbon chain.
 Hydrocarbons containing single bonds are known as alkanes. For such hydrocarbons, the primary suffix
“ane” should be added to the root word
 Hydrocarbons containing double bonds are known as alkenes. For such hydrocarbons, the primary suffix
“ene” should be added to the root word.
 Hydrocarbons that contain a triple bond between carbon atoms are known as alkynes and for naming
such hydrocarbons the primary suffix “yne “should be added.
SUFFIX
Primary Suffix Secondary Suffix

6. PAGE 6
 SECONDARY SUFFIX
A secondary suffix indicates the functional group present in the carbon
compound. Functional groups are defined as specific atoms, group of
atoms or ions which are part of a larger hydrocarbon chain and impart
characteristic properties to the compounds.
 PREFIX
Prefix It is always be kept in mind that alkyl groups
forming branches of the parent chain are considered as
sidechains .
Atoms or groups of atoms such as fluoro (-F), Chloro (-
Cl) ,bromo (-Br), Ido (-I),
Nitro (-No2) and Alkoxy(-OR) are reffered to
assubstituents . Root words are profixed with the name
of the substituent orthe side chain.
 Arrangment of Prefixes, Root word and Suffixes
These are arranged a follows while writing the name in such a manner.
IUPAC name = Prefixes + Root word + Primary Suffix + Secondary suffix

7. PAGE 7
CH3–CH2–CHO
Root word : Prop
Primary suffix : an
Secondary suffix: al
Root word + Primary suffix + Secondary suffix: Propanal
CH3–COOH
Root word : Eth
Primary suffix : an
Secondary suffix: Oic acid
Root word + Primary suffix + Secondary suffix: Ethanoic acid
EXAMPLES’

8.  WHAT IS STRUCTURAL ISOMERISM
PAGE 8
The isomers that have different molecular Constitution [ i.e, Different atom-to-atom bonding
or atomic connectivity ] are "structural isomers "and this phenomenon is known as structural
Isomerism. There are 5 type of structural Isomerisms. Those are -
1
2
3
4
5
Chain isomerism - carbon atoms linked together in different order. Ex- CH3 - CH2 - CH2 - CH3 & CH3 - CH - CH3
Position isomerism - substituent group or atom occupies different positions in the carbon chain.
Ex- CH3 - CH2 - CH2 –OH & CH3 – CH – CH3
Functional group isomerism - Same in molecular formula but different in functional groups.
Ex- CH3 CH2 OH & CH3 - O - CH3
Metamerism - It is a type of isomerism having the same molecular formula but different alkyl groups on either side of functional
groups are called Metamerism. Ex-. CH3 CH2 - O - CH2 CH3 & CH3 - O - CH2 CH2 CH3
Toutomerism - It is a special type of functional Isomerism in which the isomers are in dynamic equilibrium with each other.
Ex- CH3 - C - CH2 CO2 C2 H5 & CH3 - C = CH - CO2 C2 H5
CH3
OH
[ Butane ] [ Isobutane ]
[ Propan-1-ol ] [ Propan-2-ol ]
[ Ethyl alcohol ] [ Dimethyl ether ]
[ Diethyl ether ] [ Methyl propyl ether ]
[ Keto -form ] [ Enol -form ]