Stereochemistry

Stereochemistry

•Any chemistry which involves orientation in space

Symmetry

•Referring to anything that can be divided on some plane into identical parts

Symmetry

•In molecules, planes of symmetry can be determined along any bond axis

Symmetric Compounds

•Compounds with at least one plane of symmetry

Name the Following

C C C

C-C-C-C-C-C-C

C-C

Asymmetric Compounds

•Compounds with no plane of symmetry

Symmetric Compounds

•The mirror images of symmetric compounds are identical

Symmetric Compounds• All completely

symmetric compounds are non-

polar

Asymmetric Compounds

•The mirror images of asymmetric compounds are not identical. They are optical isomers

Asymmetric Compounds

•Asymmetric compounds can be

polar if the bonds are polar

Polarity of Hydrocarbons

•Hydrocarbons are non-polar

Optical Isomers

•Mirror images of asymmetric compounds are optical isomers or stereoisomers

Stereoisomerism of C

•A carbon center must be bound to 4 different

things to be asymmetric

Stereoisomerism of C

•Any carbon center bound to 3 or less

things has at least one plane of symmetry

Stereoisomerism of C

•Use modeling

Stereoisomerism of Carbon Chains

•The constituents on two adjacent carbons spend

more time in the staggered position

Stereoisomerism of Carbon Chains

•Use modeling to show aligned & staggered

positions

Diffusion

•Movement down an energy gradient

Thermochemistry•Compounds will

eventually move to the lowest possible energy state (the most stable

state)

Thermochemistry of Organic Compounds•Stability is sometimes determined by how the

compound interferes with its surroundings

Thermochemistry of Organic Compounds•To increase stability,

organic compounds tend to curl up

Thermochemistry of Organic Compounds

•Organic compounds ring structures are more stable than their corresponding straight chain structures

Drill: Name:

Draw an optical isomer of:

H3C-CH2

H3C-C-CH2-CH2-CH3

H

Draw & Name at least 5 isomers of

C6H14