ORGANIC CHEMISTRY

Classification of organic compounds.

(1). Acyclic or open chain compound :-

These compounds contain open chain of carbon atoms in ther molecules. The carbon chains may be either stright chains or branched chains. They are also called aliphatic compounds .

(2). Cyclic or close chain or ring structure :-

These compounds contain chains or ring structure of atoms in their molecules.

Alicyclic compounds:-

These compounds contain a ring of three or more carbon atom in them. They resemble aliphatic compounds in many of their properties.

AROMATIC COMPOUNDS:-

These have a cyclic system containing at least one benzene ring. The parent member of the family is called benzene. Benzene has a homocyclic hexagonal ring of six carbon atoms with three double bonds in the alternate position.

These compounds are also called benzonoid compounds and they exhibit special property known as aromaticity. Bicyclic and tricyclic compounds also belongs to this category.

In addition to these there are some compounds which show aromaticity but do not contain any benzene ring. These are called non-benzenoids.

Heterocyclic compounds:-

In these compounds the ring contains one or more atoms of either nitrogen,oxygen or sulpher in addition to carbon atoms. The atom other than carbon (such as N, O, S) in the ring is called hetro atoms.

Functional or characteristic groups

An atom or group of atoms which largely determine the properties of the organic compounds particularly the chemical properties are known as Functional groups.

Homologous series:-

Homologous series may be defined as "a series of similarly constituted compounds in which the members possess the same functional group and have similar Chemical characteristics". The two consecutive members differ in their molecular formula by  -CH²- group.

All the member in a particular homologous series have the same general formula.

Nomenclature of organic compounds:-