Nomenclature of Saturated Hydrocarbons their Rules

Nomenclature is a system of terms or rules that are used for forming these terms or names in a distinct field of science and arts. In simple terms it is an assignment of names to organic compounds. Saturated hydrocarbons are organic compounds that consist of carbon and hydrogen single bonds. In these compounds, there is the maximum number of hydrogen atom present for every carbon atoms. For example alkanes.

Saturated Hydrocarbons IUPAC IUPAC Naming Rules

The saturated hydrocarbons are named according to the following rules:

Longest Chain Rule: The parent chain of the compound is considered the longest chain of carbon atoms.

Lowest Set of Locants: The numbering of the carbon atoms starts from the end which gives the lowest number to the carbon atom carrying the substituent.

Presence of Same Substituent More Than Once: Prefixes such as di, tri, etc are given to the substituents which are present twice, thrice respectively on the parent chain.

Naming Different Substituents: If more than one substituent is present then the substituents are arranged in their alphabetical order.

Naming Different Substituents At Equivalent Positions: If two different substituents are present in the same position from the two ends then the substituents are named so that the substituent which comes first in the alphabetical order gets the lowest number.

Naming The Complex Substituents: Naming of the complex substituent is done when the substituent on the parent chain has a branched structure (i.e complex structure). These substituents are named as a substituted alkyl group and the carbon atom of this substituent attached to the parent chain is numbered 1. The name of this type of substituent is written in brackets.

Let us understand it with the help of an example:

Nomenclature is a system of terms or rules that are used for forming these terms or names in a distinct field of science and arts. In simple terms it is an assignment of names to organic compounds. Saturated hydrocarbons are organic compounds that consist of carbon and hydrogen single bonds. In these compounds, there is the maximum number of hydrogen atom present for every carbon atoms. For example alkanes.

In this case, we have 9 carbon atoms in the straight chain. 5th Carbon atom from both the ends of the straight-chain, consists of substituents having 3 carbon chains. On the first two carbon atoms of the substituent group, there is one additional carbon atom attached.

Now if we consider this as a new parent chain, it has a substituent which has one additional carbon each. For naming them we will firstly number the parent chain. In this case, we have 9 carbon atoms in a straight chain which is also the parent chain. Then we find that the substituent is in the fifth position.

Nomenclature is a system of terms or rules that are used for forming these terms or names in a distinct field of science and arts. In simple terms it is an assignment of names to organic compounds. Saturated hydrocarbons are organic compounds that consist of carbon and hydrogen single bonds. In these compounds, there is the maximum number of hydrogen atom present for every carbon atoms. For example alkanes.

Now taking the substituent we will observe that we have 3 substituent carbons and out of these three, two substituents have additional carbons attached. We find that the longest chain in this can be the first four carbon atom chains but this is wrong as the last carbon is not attached to the parent chain.

So we will consider only three carbon atom chains as the main chain. Thus it can be named propane and in the first and second position, we have methyl group. We can write the name as 1-2 Dimethyl propane, but it will be written as 1-2 Dimethyl propyl as it is a substituent group.

Nomenclature is a system of terms or rules that are used for forming these terms or names in a distinct field of science and arts. In simple terms it is an assignment of names to organic compounds. Saturated hydrocarbons are organic compounds that consist of carbon and hydrogen single bonds. In these compounds, there is the maximum number of hydrogen atom present for every carbon atoms. For example alkanes.

Now taking the substituent with the parent chain we will get 5-(1-2-Dimethyl Propyl) and as the parent chain has 9 carbon atoms so, it will be named nonane. Thus, the final name of the compound will be 5-(1-2-Dimethyl Propyl)nonane.

Nomenclature is a system of terms or rules that are used for forming these terms or names in a distinct field of science and arts. In simple terms it is an assignment of names to organic compounds. Saturated hydrocarbons are organic compounds that consist of carbon and hydrogen single bonds. In these compounds, there is the maximum number of hydrogen atom present for every carbon atoms. For example alkanes.

Er. Neeraj K.Anand is a freelance mentor and writer who specializes in Engineering & Science subjects. Neeraj Anand received a B.Tech degree in Electronics and Communication Engineering from N.I.T Warangal & M.Tech Post Graduation from IETE, New Delhi. He has over 30 years of teaching experience and serves as the Head of Department of ANAND CLASSES. He concentrated all his energy and experiences in academics and subsequently grew up as one of the best mentors in the country for students aspiring for success in competitive examinations. In parallel, he started a Technical Publication "ANAND TECHNICAL PUBLISHERS" in 2002 and Educational Newspaper "NATIONAL EDUCATION NEWS" in 2014 at Jalandhar. Now he is a Director of leading publication "ANAND TECHNICAL PUBLISHERS", "ANAND CLASSES" and "NATIONAL EDUCATION NEWS". He has published more than hundred books in the field of Physics, Mathematics, Computers and Information Technology. Besides this he has written many books to help students prepare for IIT-JEE and AIPMT entrance exams. He is an executive member of the IEEE (Institute of Electrical & Electronics Engineers. USA) and honorary member of many Indian scientific societies such as Institution of Electronics & Telecommunication Engineers, Aeronautical Society of India, Bioinformatics Institute of India, Institution of Engineers. He has got award from American Biographical Institute Board of International Research in the year 2005.