Isomerism

What are the ISOMERISMS [2] and their definitions?

• Structural isomerism: molecules with same molecular formula, BUT different structural formulas.

• Stereoisomerism: molecules have the same structural formula, BUT its atoms are arranged differently in space.

What are the different types [3] of STRUCTURAL isomerism [1 & 2 & 2]?

• Chain isomerism: different carbon arrangements.

• Position isomerism: has the same functional groups, but on different carbon atoms.

• Functional group isomerism: same molecular formulas, but different functional groups.

What are the different types [2] of STEREOISOMERISM [2 & 2]?

• Optical isomerism: 1 carbon atom binds to 4 different groups.

• Geometric isomerism: a C=C double bond, binds to 2 different groups.

What is the ‘chemistry' of GEOMETRIC ISOMERS?

• Entgegen: the 2 highest priority groups are on opposite sides of the double bond.

• Zusammen: the 2 highest priority groups are on the same side of the double bond.

Why do E-Z ISOMERISM occur?

Due to the restricted rotation around the C=C double bond.

How are CIP priority rules [2] used to decide which groups are higher priority?

• A high atomic number = high priority.

• You compare the attached atoms in the chain.

What characteristics do the homologous series have [5]?

• General formula.

• Chemically similar.

• Same functional groups.

• Shows a trend in physical properties.

• Successive molecules contain a successive CH2.