Optical isomerism Flashcards
What is optical isomerism?
A form of stereoisomerism, where 2 molecules have the same structural formula but different arrangement of atoms in space.
Optical isomers are non-superimposable mirror images of each other and have a chiral carbon atom.
What is a chiral molecule?
A chiral molecule has 4 different groups attached to a carbon atom.
What are enantiomers?
We can arrange groups in 2 different ways around a chiral carbon atom. We call these 2 different molecules enantiomers.
These enantiomers are mirror images of each other and are non-superimposable. No matter which way you turn them they will not overlap.
What is plane polarised light?
Standard light oscillates in all directions.
When we pass the light through a polaroid filter we produce plane polarised light. This only oscillates in one direction.
How can we use plane polarised light to detect optically active compounds?
Optically active isomers will rotate plane polarised light.
One enantiomer rotates light clockwise, the other will rotate it anticlockwise.
What is a D enantiomer?
Rotates plane polarised light clockwise
What is an L enantiomer?
Rotates plane polarised light anticlockwise
When is a carbon asymmetric?
When a C atom is bonded to 4 different groups.
