Optical Isomerism Flashcards
What is a chiral carbon?
One that has four different groups attached to it
Why don’t racemic mixtures show any optical activity?
The two enantiomers cancel each-other’s light-rotating effect out
What are enantiomers?
They are molecules made by arranging the groups on a chiral carbon differently and cannot be superimposed because they are mirror images
How to Optical isomers behave in plane-polarised light?
Because they’re optically active, they rotate plane-polarised light. One enantiomer rotates it in a clockwise direction and the other rotates it in an anti-clockwise direction
What is the shape of a double bond?
Planar (flat)
What’s a racemate (racemic mixture)?
A racemic mixture contains equal quantities of each enantiomer of an optically active compound
What product is formed when a symmetrical ketone is reacted with a nucleophile?
The product will not have a chiral centre so it will not display optical isomerism
Why don’t chemists modify reactions in order to produce a single enantiomer?
Because it is difficult and expensive to do
What is a stereoisomer?
Stereoisomers have the same structural formula but have their atoms arranged differently in space
Why do chemists get a racemic mixture of a chiral product when two achiral products are reacted?
Because when two molecules react, there’s an equal chance of forming each of the enantiomers
How does Plane-polarised light behave?
It only vibrates in one direction
