Isomers

Constitutional, conformational, stereoisomers

Structural isomers that differ in the positions of their constituent atoms

Isomers that arise from different orientations around a sigma bond, which may rotate relative to one another

Either eclipsed or staggered Eclipsed > staggered, in terms of energy

The relative populations of conformational isomers are temperature dependent

Chair>twist>boat

Differ in their spatial, 3-D arrangements

When rotation about a bond or bonds is not possible due to a ring system of pi bond

Nonsuperimposable, chiral mirror images

Stereoisomers that are not Mirror images of each other Geometrical isomers are diastereomers

Have identical physical and chemical properties; they are not easy to separate

Have different physical and chemical properties; they are easy to separate by conventional means

50-50 mixture of a pair of enantiomers

R equals right, S equals left

• ) assign priorities based on mass • ) visualize with lowest priority pointing away from you • ) rotate going 1,2,3

Have chiral centers but are not chiral overall Mirror image is identical in every way, have internal mirror plane

Optically inactive

Optically inactive

Optically active but flip in opposite direction

Plane polarized light is a group of photons that are all moving in the same direction AND have electromagnetic fields oscillating in the same place

Optically active and rotate plane polarized light