In geometric isomerism, the spatial positions of molecules are locked because of the presence of a double bond or ring structure.

In Laevo optical Isomers, the plane of polarized light is rotated to the left. In Dextro optical isomers plane of polarized light is rotated to the right. Enantiomers is the term mostly used to refer to optical isomers. In this subtype of Stereoisomerism, carbon atoms are connected to four different groups and this is known as the chiral center. In optical isomerism, the isomer Compounds differ in terms of optical activity but are mirror images of each other. Example - 1,2 - dichloroethene (C 2H 2CI 2) The phenomenon when compounds start showing different spatial arrangements of atoms even when their molecular formula is the same is termed Stereoisomerism. Example - 1-Chloropropane and 2-Chloropropane Stereoisomerism In Positional isomerism, the functional groups and substituents of a structural isomer will have different positions.

Example - Methoxy-propane (CH 3OC 3H 7) & ethoxyethane (C 2H 5OC 2H 5) Compared with other types of isomerism, metamerism is rarely found and is constrained to molecules with atoms. In metamerism, each side of the functional group has the presence of different alkyl chains. The functional group of Ethanol is ‘OH’ while the Functional group of dimethyl ether is ‘R-O-R’. They both have the same molecular formula C 2H 6 O. In functional isomerism, the isomer compounds with different functional groups have the same molecular formula. Tautomers take place in an equilibrium state as they can easily interchange. In tautomerism, there will be a difference in isomer compounds only in the position of electrons, protons, and atoms. Example- 2 methyl butane, 2-2 dimethyl propane, and n-pentane. Skeleton isomerism is the other term used to refer to chain isomerism. In chain isomerism, there will be different branches of carbon atoms in multiple isomers compounds but still, their molecular formula remains the same. The number of pi bonds in ring chain isomers will be different. These kinds of compounds are known as ring chain isomers and this phenomenon is termed ring chain isomerism. In the ring chain isomerism, there will be an open-chain structure in any one of the isomers and the remaining will have a closed chain or a ring structure. Structural Isomerism can further be classified into various types such as chain isomerism, positional isomerism, functional isomerism, metamerism, ring-chain isomerism, and tautomerism.

The phenomenon when the compounds start showing isomerism because of their different structure is termed Structural Isomerism. Read More: Isomerism in Coordination Compounds Structural Isomerism Optical Isomerism & Geometric Isomerism are the two subtypes of Stereoisomerism. Ring Chain Isomerism, Chain Isomerism, Tautomerism, Functional Isomerism, Metamerism, and Positional Isomerism are the subtypes of Structural Isomerism. Isomerism can be differentiated by primary types and their subtypes. In simple words, multiple compounds having the same molecular formulae but different structural formulae are referred to as isomers and this entire phenomenon is described as ‘Isomerism’. ‘Isos’ and ‘meros’ are Greek words that translate to ‘equal parts’.

Asymmetric carbon atom