What is an enantiomer?
A molecule that is not identical to its mirror image; a kind of stereoisomer
What is chiral?
A molecule that is not identical to its mirror image
What makes a structure not chiral?
A plane of symmetry
What is a plane of symmetry?
A Plane that cuts through the middle of a molecule (or any object) in a way that one half of the molecule or object is a mirror image of the other half.
What is achiral?
A molecule that has a plane of symmetry
What is the cause of chirality?
the presence of a tetrahedral carbon atom bonded to four different groups
Example of chirality center
Central carbon atom connected to four groups
What is it to be optically active?
When a beam of plane-polarized light passes through a solution of certain organic molecules, the plane of polarization is rotated by an angle.
Levoratory?
Left- counterclockwise (-)
Dextrorotatory?
Right- clockwise (+)
What is specific rotation formula?
Observed rotation
Pathlength
Concentration
Enantiomers aka (optical isomers) have what traits?
They have the same melting point and boiling point, but they differ in the direction in which their solutions rotate plane-polarized light.
What are sequence rules (Cahn–Ingold–Prelog rules)?
Rank the four groups attached to the chirality center and then looks at the handedness with which those groups are attached.
What is a diasteromer?
stereoisomers that are not mirror images.
What is the difference between enantiomer and diasteromer?
- Enantiomers have opposite configurations at all chirality centers
- Diastereomers have opposite configurations at some (one or more) chirality centers but the same configuration at others.
What are epimers?
Two diastereomers differ at only one chirality center but are the same at all others
What is a racemic mixture?
A 50 : 50 mixture of the two chiral molecules or enantiomers.
Why racemates show no optical rotation?
the (+) rotation from one enantiomer exactly cancels the (−) rotation from the other.
Resolution
Is the separation of enantiomers through crystallization
Constitutional Isomers
Are compounds were the atoms are connected differently.
Stereoisomer
Compound where the atom is connected in the same order but different in space.
What is a subclass of diasteromers?
Cis and trans
What is a nitrogen tetrahedral?
Nitrogen with three covalent bonds and a lone pair that acts as a "fourth" substituent
What is a prochiral molecule
A molecule that interconverts from achiral to chiral
What can be prochiral?
planar, sp 2 -hybridized atoms, compounds with tetrahedral, sp 3 -hybridized atoms
Pro-R is?
the atom whose replacement leads to an R chirality center
What has different biological properties but identical physical properties?
Enantiomers
What is a chiral environment?
To be chemically distinctive