E/Z isomerism

Stereoisomers

Same structural formula but a different arrangement of atoms in space ( the way they are arranged spatially around the carbon).

E/Z stereoisomers conditions

• A carbon-carbon double bond must be present, as there is restricted rotation

• Each carbon in the double bond must be attached to two different groups

Cis-trans isomerism

A special type of E/Z isomerism where two carbon atoms either side of the bond have at least one group in common.

It does not work when there are more than two different groups attached around the double bond.

CIP priority rules

Mr Cahn, Mr Ingold and Mr Prelog, came up with a solution to help assign priority rules to determine E-isomers and Z-isomers.

Highest priority group is the one with the highest atomic number directly bonded to the carbon atom