Organic and Inorganic Chemistry Lesson of the Day – Stereoisomers

Two molecules are stereoisomers if they

  • have the same molecular formula
  • have the same sequence of bonds between each molecule’s constituent atoms
  • have different 3-dimensional (spatial or geometric) orientations of the constituent atoms

Examples of stereoisomers include

It is important to emphasize that stereoisomers are defined for 2 or more molecules.  Consider 3 isomers, A, B and C.

  • A and B may be stereoisomers.
  • A and C may not be stereoisomers.  They may be structural isomers, which have the same atoms but different sequences of bonds.