Skip to main content

NOMENCLATURE PART 1

 NOMENCLATURE 

Mainly three systems are adopted for naming an organic compound -
  1. Common names or Trivial system 
  2. Derived system 
  3.  IUPAC system or Jeneva system

Trivial System :

Initially organic compounds are named on the basis of source from which they were obtained for

 S.no

 Organic Compound

 Trivial Name

 Source

 1.

CH3OH 

 Wood spirit or Methyl spirit

Obtained by destructive distillation of wood 

 2.

NH2CONH2 

 urea 

 obtained from urine 

 3.

 CH4

 Marsh gas (fire damp)

It was produce in marshy places 

 4.

CH3COOH 

 vinegar 

obtained from acetum- i.e vinegar  

 5.


 

 Oxalic acid 

obtained from oxalis plant 

 6.

HCOOH  

Formic acid  

Obtained from formicus (red ant) 

 7.


 

 Latic acid  

Obtained from sour milk  

 8.


 

 Malic acid 

obtained from apples  

 9.

 CH3CH2CH2COOH

 Butyric acid 

obtained from butter  

 10.

CH3(CH2)4COOH 

 Caproic acid 

obtained from goats  

Some typical compounds in which common & trivial names are also differ.

 s.no

 Compound

Trivial Name  

Common name 

 1.

 CH4

 Marsh gas

 Methane 

 2.

 CH3OH

 Wood spirit 

 Methyl alcohol

 3.

 CH3COOH

 Vinegar 

 Acetic acid 

 4.

 

 Acetone 

 Dimethyl ketone 

 5.

 

 Acrolein 

Acryl aldehyde  

 6.

 

 Pyualdehyde

 Tertiary valer aldehyde


Comman Name : 

R is termed as alkyl

 S.no

Compound 

 Name 

 1.

R-X 

 Alkyl halide 

 2.

R-OH 

Alkyl alcohol   

3. 

R-SH

 Alkyl thioalcohol 

 4.

R-NH2

 Alkyl amine 

 5.

R-O-R 

Dialkyl ether  

6. 

R-S-R 

Dialkyl thioether 

 7.

 

 Dialkyl ketone 

 8

 R-NH-R

 Dialkyl amine 

 9

 

 Trialkyl amine 

 10

 R-O-R'

 Alkyl alkyl' ether  

 11



 

 Alkyl alkyl' ketone 

 12

 R-S-R'

 Alkyl alkyl thioether 

 13

 R-NH-R'

 Alkyl alkyl amine 

 14

 

 alkyl alkyl' alkyl" amine 

 Position of double bond : 

In an unsaturated hydrocarbon if the position of double bond is on Ist or last carbon then it's prefix will be 𝝰(alpha) if it is on 2nd carbon it is termed as ꞵ (Beta) & then 𝛾(gamma) & 𝞭 (delta) and so on.

Example : 

H2C=CH–CH2–CH3                         𝝰-butylene 

H3C–CH=CH–CH3                       ꞵ -butylene 

H3C–CH2–CH=CH2                         𝝰-butylene 

H2C=CH–CH3          or                  propylene         (Both are same positions propylene, isobutylene)

   
                            Isobutylene 


CH3–CH2–CH=CH–CH2–CH3                    𝛾-hexylene 

CH3–CH2–CH2–CH=CH–CH2-CH2–CH3   𝞭-octylene

Common - Naming of dihalides :

 (a) When two same halogen atoms are attached to the same carbon such compounds are called Gemdihalides.
 (b) Common names of such compounds are alkylidene halides.
Example:


Exception :



 
(c) When two same halogen atoms are attached to adjacent carbon, these are called as vicinal dihalides. Common names of such compounds are alkylene halide.








(d) When two same halogen atoms are attached at the two ends of a carbon chain its common naming will be polymethylene halide.
 'poly' word indicates the number of –CH2– groups. 
–CH2–            2    3     4          5       6 
Poly              di    tri  tetra   penta   Hexa
Example :





Exception :

 



Common - Naming of di-hydroxy compounds : 

(a) When two –OH groups are attached to adjacent carbon's they are termed as alkylene glycol.







(b) When two –OH groups are attached at the two ends of a carbon chain, these compounds are named as polymethylene glycol. 
Poly ⟶Number of >CH2 groups.
Example:





Exception:





Ex : Make the structure of following organic compounds -
1.Isopropylidene Bromid







2.Isobutylene glycol 







3.Trimethylene glycol






Common - Naming of the functional group having carbon :

                        chart 1

 S. No.

Functional group  

suffix  

 1.

 

 Aldehyde

 2.

 

 Oic acid

 3.

 

 yl halide

 4.

 

 Amide

 5.

 

 o-nitrile

 6.

 

 o-isonitrile

 7.

 

 ate

 8.

 

 ic-anhydride

 Prefix : 

  1. Carbon ⟶ Form 
  2. Carbon ⟶Acet 
  3. Carbon ⟶ Propion













3C + (=) double bond = Acryl 
4C + double bond = Croton
Example :









Nomenclature of Ester :

The group which is attached to the oxygen is written as alkyl & the remaining structure is named same as defined in chart-1.

Examples :







Nomenclature of Anhydride :


 Rule : Add the total number of carbon atoms & divide by 2, the quotient will give you the number of carbon atom now name it according to Chart-1
Total /2 = Quotient = Number of C atom
 








If R≠ R', You need not to find out Quotient. Divide it in two parts as above & name it by suffixing ic anhydride (alphabetically) 























Derived System : 

According to this system any compound is given name according to the parent name of the homologous series. This system is reserved for the following nine homologous series.
Chart -2

 S.No

Name of Homologous series  

 Derived Name 

structure of group  

1 

Alkane  

Methane 

 2

Alkene 

Ethylene 

 3

Alkyne  

Acetylene 

 4

Alkanol 

carbinol 

 

 5

Alkanal  

Acetaldehyde  

 

 6

Alkanoic  

Acetic acid  

 

 7

Alkanoyl halide  

Acetyl 

 

 8

Alkanamide 

Acetamide  

 

 9

Alkanone  

Acetone  

 

Labels:

Comments

Post a Comment

Popular posts from this blog

Molar : Understanding the Concept and Its Significance

Demystifying Molar: Understanding the Concept and Its Significance Introduction: In the field of chemistry, the concept of the mole, often referred to as "molar," serves as a fundamental unit of measurement. The molar is a crucial concept that allows scientists to quantify and understand the relationships between atoms, molecules, and reactions. In this blog, we will delve into the fascinating world of moles, exploring their definition, significance, and applications in various aspects of chemistry. What is a Molar? Simply put, a molar is a unit of measurement used in chemistry to quantify the amount of a substance. It provides a bridge between the microscopic world of atoms and molecules and the macroscopic world of everyday measurements. The molar is defined as the amount of a substance that contains as many entities (atoms, molecules, ions, etc.) as there are atoms in exactly 12 grams of carbon-12. This definition is based on Avogadro's number, which is approximately 6
Post a Comment
Read more

Unveiling the Science Behind Washing Powders: Insights from a Chemist

Unveiling the Science Behind Washing Powders: Insights from a Chemist Introduction: In our everyday lives, we encounter numerous challenges, and one that most of us can relate to is laundry. The quest for cleaner, fresher, and more vibrant clothes has led to the development of various laundry detergents, including the ever-popular washing powders. As a chemist, I find the science behind these powders fascinating. In this blog, we will delve into the intricate world of washing powders, exploring their composition, working mechanisms, and the chemical reactions that make them effective . 1. Composition of Washing Powders: Washing powders are complex mixtures of chemicals carefully formulated to remove dirt, stains, and odors from fabrics. The composition of washing powders typically includes the following key components:  a. Surfactants:  These are the primary cleansing agents in washing powders. Surfactants contain both hydrophilic (water-attracting) and lipophilic (oil-attracting) prop
Post a Comment
Read more

Understanding Molar Concentration: A Key Concept in Chemistry

 Understanding Molar Concentration: A Key Concept in Chemistry Chemistry is the science that deals with the properties, structure, and composition of matter. One crucial concept in chemistry is molar concentration, which plays a crucial role in many chemical calculations, including stoichiometry, dilution, and reactions. In this blog post, we will delve into the fundamentals of molar concentration and explore its significance in chemical reactions and laboratory experiments. What is Molar Concentration? Molar concentration, also known as molarity, is a measure of the amount of solute dissolved in a given volume of solution. It is defined as the number of moles of solute per liter of solution and is denoted by the symbol "M." The molar concentration of a solution is determined by dividing the number of moles of solute by the volume of the solution in liters. The formula for molarity is Molarity (M) = moles of solute / volume of solution (in liters) For example, if you dissolve
Post a Comment
Read more