Confusing shit

Enantiomers, Chirality and more

Cis

same side

Trans

opposite side

axial position

up and down on chair conformation (vertical lines) (A)

equatorial position

left and right on chair conformation (horizontal lines) (E)

Chiral

• Objects that are non-superimposable on their mirror images

• Ex: left and right hands, left and right ears

Achiral

• Mirror image is superimposable (rotate molecule 180 degrees)

• Have at least 1 plane of symmetry

• Ex: chair, fork

Mirror image

Relfection

Chiral center (stereocenter)

A carbon atom bonded to four different groups

Enantiomers

• non-superimposable stereoisomers

• mirror images

• If one is RR, the other has to be SS

• Switch all chiral centers

• Identical physical and chemical properties (in achiral environments)

Superimposable

• Means that two objects can be placed on top of each other and align perfectly (identical).

• Ex: pen or pencil, stack of plates, two sheets of paper

R stereocenter

clockwise rotation

S stereocenter

counterclockwise rotation

diastereomers

• non-superimposable stereoisomers

• non-mirror images

• If one is RS there other has to be SR

• Switch at least one but not all chiral centers

• Different compounds with different physical and chemical properties (in chiral environments)

stereoisomer

Same molecular formula, same connectivity of atoms, different orientations of atoms in space

meso compound

• Have superimposable mirror images

• Achiral

• 2 or more chiral centrals, but all are achiral

constitutional isomer

Same molecular formula, different connectivity of atoms

plane polarized light

oscillates in only one plane

ordinary light

oscillates in all planes perpendicular to the direction of propagation

Racemic mixture

• Equal amount of two enantiomers (optically inactive)

• Not going to react with plan-polarized light