Organic Compounds - Classification 0f Organic Compounds

 What are organic compounds?

The compounds in solid, liquid or gaseous state which contain carbon in its molecule are known as organic compounds. There are a large number of organic compounds and therefore a proper systematic classification was required. Organic compounds can be broadly classified as acyclic (open chain) or cyclic (closed chain).

1. Acyclic or open chain compounds:

These compounds are also known as aliphatic compounds, they have branched or straight chains. Following are the examples in this category.

2. Alicyclic or closed chain or ring compounds:

These are cyclic compounds which contain carbon atoms connected to each other in a ring (homocyclic). When atoms other than carbon are also present then it is called as heterocyclic. Examples of this type are as follows:

They exhibit some properties similar to aliphatic compounds.

3. Aromatic compounds

They are a special type of compounds which contain benzene and other ring related compounds. Similar to alicyclic, they can also have heteroatoms in the ring. Such compounds are called heterocyclic aromatic compounds. Some of the examples are as follows:

Non-benzenoid aromatic compounds

4. Heterocyclic aromatic compounds

Organic compounds can also be classified on the basis of functional groups into families or homologous series.

Functional group

The functional group can be defined as an atom or a group of atoms that are joined together in a specific manner which is responsible for the characteristic chemical properties of organic compounds. Examples, in this case, are the hydroxyl group -OH, aldehyde group -CHO and carboxylic acid group -COOH.

Homologous series

A group or a series of organic compounds in which each member contains the same characteristic functional group and differs from each other by a fixed unit form a homologous series and therefore its members are known as homologous.

The members of the homologous series can be represented by a general formula and the successive members differ from each other in the molecular formula by a CH2 unit. There are a number of homologous series in organic chemistry such as alkanes, alkenes, alkynes, haloalkanes, alkanols, amines etc.