Nomenclature and Isomers

4

Shows every atom and every bond in the molecule

Shows the unique arrangement of atoms in a molecule without showing all the bonds e.g CH3CH3

Simplified displayed formula where each vertex represents a carbon atom and each line is a C-C bond and each carbon is assumed to have enough C-H bonds to make a total of 4 bonds. e.g - is ethane

Look for the longest chain of C atoms and name it. Identify any side chains and add the name to the front. Find the number carbon atom of the chain it is attached to and add this before the side chain name (count from which ever end gives you the lowest number). If there are more than one of the same side chain add all the carbon atom number to the front and add a suitable prefix to the side chain name e.g di-

An atom or group of atoms in an organic molecule which is responsible for the characteristic reactions of that molecule.

RCOR

RCOH

Molecules with the same molecular formula but with different arrangements of the atoms.

Where the hydrocarbon chain has the same functional group but is arranged differently. e.g butane and 2-methyl propane

The same functional groups or side chains are attached to different positions on the same main chain.

The functional groups are different but there is the same molecular formula e.g aldehydes and ketones

Where two or more compounds have the same structural formula but they differ in the arrangement of the bonds in space.

Identify the heaviest element bonded to each carbon either side of a C=C. If they are on opposite sides the add (E)- to the start of the name. If they are on the same side add (Z)- to the start of the name. (Only works with double bonds because the carbons either side can’t rotate).

The hydrogen atoms in ammonia have been replaced by aryl or alkyl groups. It is a primary amine when only one H is replaced, (etc. up to 3 Hs)

CN (3 double bonds)

A family of organic compounds with the same functional group but different carbon chain lengths.