Isomerism

Isomers are molecules that have the same molecular formula but atoms arranged differently

There are two types of isomerism, being structural isomerism and stereoisomerism

Structural isomers are organic compounds which have the same molecular formula but different structural formulae

1* Positional isomerism 2* Functional group isomerism 3* Chain isomerism

Positional isomerism is when the same functional groups are attached to the main chain but at different points

Functional group isomerism is when the functional groups attached to the main chain are different

Chain isomerism is when there is a different arrangement of the hydrocarbon chain

Stereoisomerism is when two (or more) compounds have the same structural formula, with groups of atoms arranged differently in space

There is E-Z isomerism and Optical isomerism

An E isomer shows atoms or groups of atoms on the opposite sides of the C=C bond A Z isomer shows atoms or groups of atoms on the same sides of the C=C bond

Cis isomers represent isomers which have both functional groups on the same side above/below the carbon double bond Trans isomers represent isomers which have the functional groups on opposite sides

E notations are equivalent to Trans notations Z notations are equivalent to Cis notations

Cahn - Ingold - Prelog rules 1) You would look at the atoms directly attached to the carbon 2) Then the atom with the highest atomic number has the highest priority