Nomenclature and Isomerism

Nomenclature and Isomerism

New Functional Groups

New Functional Groups

Compound type Group structure Example
Carboxylate salt Soaps
Acyl choride Ethanoyl Chloride
Acid anhydride Ethanoic Anhydride
Amide Ethanamide
Ester Ethyl Ethanoate

You should also be aware of a few other amine and related molecules

Molecule Group structure Example
Secondary amine Dimethylamine
Tertiary amine Trimethylamine
Alkyl ammonium salt Benzalkonium Chloride

Nomenclature of new groups

Compound/molecule Suffix Prefix Additional notes Example
Carboxylate salts -anoate The cation is first Sodium methanoate
Acyl chlorides -anoyl chloride No numbering is needed Ethanoyl chloride
Acid anhydrides -anoic or aklyl Same alkyl group: ethanoic anhydrideDifferent alkyl groups: methanoic ethanoic anhydride
Amides -anamide No numbering is needed Propanamide
Esters -anoate alkyl- Methyl methanoate
N-substituted amides -anamide N-alkyl- N-ethyl ethanamide
Primary amines -ane amino- Amino should be preceded by the number 2-aminopropane
Secondary amines -ane N-alkyl- The longest chain is name after the suffix N-methyl, 2-aminopropane
Tertiary amines -ane N-alkyl- The longest chain is name after the suffix N-methyl, N-ethyl, 1-aminopropane
Alkylammonium salts -ammonium chloride They are either primary, secondary, tertiary or quaternary Dimethyldiethylammonium chloride

Nomenclature of Compounds containing more than one Functional Group

A Level Chemistry – A lot of organic compounds are composed of more than one functional group. These compounds are more complicated to name but you will only need to be aware of a few of these combinations. For A2 Chemistry you should be particularly familiar with amino acids and hydroxynitriles.

Functional groups Prefix Additional notes Examples
One is an amine or a haloalkane Simply add the necessary prefix 3-aminopropanoic acid

3-chlorobutan-2-olOne is an alcohol and the other a nitrate or contains a C=O bondThe alcohol group: hydroxy- 2-hydroxypropanoic acidOne is an alcohol and the other anything but an amine or haloalkane The -an part is replaced by -en and the position of the alkene is specifiedBut-1-en-4-ol