A chiral molecule exists as two optical isomers, also called enantiomers. They are non-superimposable mirror images of each other. Optical isomerism is a type of stereoisomerism: both isomers have the same structural formula, but a different arrangement of groups in space.Drawing optical isomers: use 3D formulae around the chiral carbon.
• Draw two bonds in the plane of the paper as ordinary lines.
• Draw one bond coming towards you as a solid wedge.
• Draw one bond going away from you as a dashed wedge.
Then draw the second isomer as the reflection of the first, with a vertical dashed line between them to represent the mirror.
• They have identical physical properties, such as melting point, boiling point and density.
• They have identical chemical reactions with non-chiral reagents.
• They differ in their effect on plane-polarised light: they rotate it by the same angle but in opposite directions. For this reason each is described as optically active.
• They can behave differently with other chiral molecules, such as enzymes and receptors in the body. One enantiomer of a drug may be effective while the other is inactive or harmful.
• Draw two bonds in the plane of the paper as ordinary lines.
• Draw one bond coming towards you as a solid wedge.
• Draw one bond going away from you as a dashed wedge.
Then draw the second isomer as the reflection of the first, with a vertical dashed line between them to represent the mirror.
• They have identical physical properties, such as melting point, boiling point and density.
• They have identical chemical reactions with non-chiral reagents.
• They differ in their effect on plane-polarised light: they rotate it by the same angle but in opposite directions. For this reason each is described as optically active.
• They can behave differently with other chiral molecules, such as enzymes and receptors in the body. One enantiomer of a drug may be effective while the other is inactive or harmful.