optical isomerism Flashcards
What are optical stereoisomers?
Same structural formula, different spatial arrangement of atoms.
What is optical isomerism a form of?
Stereoisomerism.
What causes optical isomerism?
Chirality in molecules.
What is necessary for optical isomers to occur?
Four different substituents attached to one carbon atom.
What are the two isomers that result from optical isomerism called?
Enantiomers.
What is a chiral centre?
The carbon bonded to four different groups.
How is a chiral centre often indicated in formulae?
By *.
What is the three-dimensional shape of optical isomers?
Tetrahedral.
What is plane polarised light?
Light that vibrates in one plane after passing through a polaroid.
What instrument is used to measure optical rotation of enantiomers?
Polarimeter.
What does it mean for a compound to be optically active?
It can rotate the plane of polarised light.
What is a racemic mixture?
A mixture of equal amounts of enantiomers.
What is the effect of a racemic mixture on plane polarised light?
It is optically inactive.
Which enantiomer rotates plane polarised light clockwise?
+ (positive).
Which enantiomer rotates plane polarised light anticlockwise?
- (negative).
Why are many drugs produced as one enantiomer only?
Only one enantiomer has the desired effect.
True or False: Optical isomers are identical.
False.
Fill in the blank: Optical isomers are said to be ______.
Chiral.
What happens to the effect of enantiomers in a racemate?
They cancel out each other’s effect.
