What is the Difference Between Structural Isomers and Stereoisomers?

The main difference between structural isomers and stereoisomers lies in the arrangement of atoms and the spatial orientation of groups in the molecule:

• Structural Isomers: These isomers have the same molecular formula but a different bonding arrangement among the atoms. They differ in the connectivity between the atoms that constitute the compound.
• Stereoisomers: These isomers have identical molecular formulas and arrangements of atoms. They differ from each other only in the spatial orientation of groups in the molecule.

There are several types of stereoisomers, including enantiomers, diastereomers, geometric isomers, and conformers. Enantiomers and diastereomers are optical isomers, which can be differentiated by their ability to rotate plane-polarized light in opposite directions or not at all, respectively. Geometric isomers arise from the restricted rotation about a double bond or ring system, such as cis and trans isomers. Conformers are stereoisomers that show the same compound with different carbon-carbon bond orientations.

Comparative Table: Structural Isomers vs Stereoisomers

Here is a table comparing structural isomers and stereoisomers:

The key difference between structural isomers and stereoisomers is that structural isomers have the same chemical formula but different atomic arrangements, whereas stereoisomers have the same chemical formula and atomic arrangement, but different spatial arrangements.