Stereoisomerism - Optical Isomerism Flashcards
sometimes mirror images can be…
non-superimposable
different compounds
when does optical isomerism rise?
-molecule contains carbon atoms bonded to 4 different groups
The isomers are no-superimposable mirror images of one another.
what is the carbon called in mirror images
chiral or asymmetric
what is the molecule called in the mirror images
chiral or optically active
what are optical isomers?
enantiomers
what are enantiomers distinguished by?
+/-
d/l
D/L
R/S (which is more correct)
is there is a 50/50 mixture of enantiomers it is known as:
racemic mixture or racemate
what do enantiomers have?
identical physical and chemical properties
e.g boiling point
how are enantiomers distinguished by?
effect on plane polarised light
how will the plane polarised light rotate if the enantiomer is +
rotate clockwise
how will the plane polarised light rotate if the enantiomer is -
rotate anti-clockwise
how will the plane polarised light rotate if the enantiomer is 50/50
no overall effect overall
how do chiral molecules react with other chiral molecules?
they react differently
many natural molecules are…
chiral and most natural reactions are affected by optical isomerism
are amino acids chiral?
yes
what happens when protein is broken down?
we will find that the amino acid we have from this would/or be an isomer that rotates plane polarised light to the left
how do the enantiomers work in drugs?
only one enantiomer exhibits beneficial effect
Describe the importance of optical isomerism with respect to pharmaceuticals.
Chiral molecules often react differently with other chiral molecules. Most amino acids
are chiral and as a result proteins are chiral.
Many drugs are optically active and often only one enantiomer exhibits a beneficial
effect. Sometimes the other enantiomer can even be harmful.
