Isomerism: Structural, Geometric, and Optical
Start with the big picture
Isomerism is classified broadly as structural isomerism or stereoisomerism. Structural isomers have different atom connectivity; examples include chain, position, and functional-group isomers, as well as tautomers that interconvert between structures. Stereoisomers have the same connectivity but differ in spatial arrangement. Geometric isomerism arises when rotation is restricted, as in certain double bonds or rings, and may be described using cis/trans or E/Z notation. Optical isomerism concerns chiral molecules and includes enantiomers, which are non-superimposable mirror images, and diastereomers, which are not mirror images. Recognizing these categories provides a foundation for understanding how molecular arrangement can influence pharmaceutical properties and receptor interactions.
What you'll learn
- Distinguish structural isomers from stereoisomers by comparing atom connectivity and spatial arrangement.
- Identify chain, position, functional-group, and tautomeric forms of structural isomerism.
- Explain how restricted rotation gives rise to geometric isomerism and cis/trans or E/Z descriptions.
- Differentiate enantiomers, diastereomers, and meso compounds using their stereochemical relationships.
- Relate isomerism to differences in physical, chemical, and pharmaceutical properties.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
