Constitutional Stereoisomers Isomerism Constitutional Stereoisomers

Isomers Different compounds that have the same molecular formula. C5H12

Structural Formulas for C4H10O Isomers Kekulé Formula Condensed Formula Shorthand Formula

Constitutional Isomers Constitutional isomers can be: Skeletal Functional Positional Also referred to as structural isomers, are compounds that differ from each other in connectivity. Connectivity is the order of the attachment of atoms to each other.

Constitutional isomers can be: Skeletal Functional Positional C6H14

Constitutional isomers can be: Skeletal Functional Positional C5H12O

Constitutional isomers can be: Skeletal Functional Positional C5H12O

Constitutional isomers can be: Skeletal Functional Positional C4H8

Constitutional isomers can be: Skeletal Functional Positional C5H12O

Constitutional isomers can be: Skeletal Functional Positional C5H12O

Constitutional isomers can be: Skeletal Functional Positional C4H8

Stereoisomers are compounds whose atoms are connected in the same way but with different geometry or configuration. Configuration is the arrangement of atoms or group of atoms in space at the stereocenter. Stereocenter is a carbon atom bearing other atoms or groups of atoms whose identities are such that an interchange of the two groups produces a stereoisomer.

Stereoisomers can be: Geometric Isomer Optical Isomer Cis Enantiomers Trans Diastereomers E R Z S

Conformations The different arrangement of atoms that result from rotation around a single bond. A specific conformation is called a conformer (Conformational isomer) Eclipsed / Staggered (for alkane) Chair (for cyclohexane) Unlike constitutional isomers, different conformers usually interconvert too rapidly for them to be isolated

Conformations Chemists represents conformers in two ways: Sawhorse representation Newman projection

The Cis and Trans configuration of 2-Butene: Trans-2-Butene Cis-2-Butene

The Cis and Trans configuration of 1,4-Dimethycyclohexane Cis- 1,4-Dimethylcyclohexane Trans- 1,4-Dimethylcyclohexane

The E and Z configuration of 3-methyl-2-pentene: Z-3-methyl-2-pentene E-3-methyl-2-pentene

Enantiomers Isomers that are mirror images of each other but are non-superimposable Enantiomers have identical physical properties, except for the direction of rotation of the plane of a polarized light. Enantiomers have identical chemical properties except toward optically active reagents.

Enantiomers

Diastereomers have different physical properties. Isomers that are non-mirror images of each other and are non-superimposable. Diastereomers have similar chemical properties, since they are members of the same family. Diastereomers have different physical properties.

Diastereomers

The R and S configuration of Bromochloroiodomethane: R (Latin: rectus, right) S (Latin: sinister, left)

Chiral Carbon A carbon where four different atoms or group of atoms are attached to.

Constitutional isomer Practice Exercise: 1) Tell whether the given pair of compound are constitutional isomers, stereoisomers, same compound or not an isomer. Constitutional isomer (positional)

Constitutional isomer Practice Exercise: 2) Tell whether the given pair of compound are constitutional isomers, stereoisomers, same compound or not an isomer. Constitutional isomer (functional)

Constitutional isomer Practice Exercise: 4) Tell whether the given pair of compound are constitutional isomers, stereoisomers, same compound or not an isomer. Constitutional isomer (skeletal)