Nomenclature and Structure of Organic Substances
This is part of HSC Chemistry course under the topic of Nomenclature.
HSC Chemistry Syllabus
-
investigate the nomenclature of organic chemicals, up to C8, using IUPAC conventions, including simple methyl and ethyl branched chains, including: (ACSCH127)
Nomenclature and Structure of Organic Substances
Organic chemistry is a significant component of the HSC Chemistry curriculum. Central to this branch of chemistry are organic functional groups, which are specific groups of atoms within molecules responsible for their characteristic properties and reactions. Understanding the nomenclature and structure of these functional groups is crucial for mastering organic chemistry concepts. This summary aims to provide an overview of common organic functional groups, their structure, and naming conventions.
We highly recommend you learn the nomenclature and structure of each organic functional group together with its physical properties and chemical reactivities.
Alkanes
Structure: Alkanes are hydrocarbons containing only single carbon-carbon (C-C) and carbon-hydrogen (C-H) bonds. They are saturated hydrocarbons, meaning they contain the maximum number of hydrogen atoms possible.
Nomenclature: Alkane names end with the suffix "-ane" and use a prefix to indicate the number of carbon atoms (e.g., methane, ethane, propane, butane).
Alkenes
Structure: Alkenes are hydrocarbons containing at least one carbon-carbon double bond (C=C). They are unsaturated hydrocarbons, meaning they have fewer hydrogen atoms than alkanes with the same number of carbon atoms.
Nomenclature: Alkene names end with the suffix "-ene" and use a prefix to indicate the number of carbon atoms (e.g., ethene, propene, butene). The position of the double bond is specified with a number before the name (e.g., 1-butene, 2-butene). The position can also be denoted within the name (e.g., but-1-ene, but-2-ene).
Alkynes
Structure: Alkynes are hydrocarbons containing at least one carbon-carbon triple bond (C≡C). They are also unsaturated hydrocarbons.
Nomenclature: Alkyne names end with the suffix "-yne" and use a prefix to indicate the number of carbon atoms (e.g., ethyne, propyne, butyne). The position of the triple bond is specified with a number before the name (e.g., 1-butyne, 2-butyne). The position can also be denoted within the name (e.g., but-1-yne, but-2-yne).
Alcohols
Structure: Alcohols contain a hydroxyl functional group (OH) bonded to a carbon atom.
Nomenclature: Alcohol names end with the suffix "-ol" and use a prefix to indicate the number of carbon atoms in the parent chain (e.g., methanol, ethanol, propanol). The position of the hydroxyl group is specified with a number before the name (e.g., 1-propanol, 2-propanol). The position can also be denoted within the name (e.g., propan-1-ol, propan-2-ol).
Aldehydes
Structure: Aldehydes contain a carbonyl functional group (C=O) bonded to a terminal carbon atom and a hydrogen atom.
Nomenclature: Aldehyde names end with the suffix "-al" and use a prefix to indicate the number of carbon atoms in the parent chain (e.g., methanal, ethanal, propanal). Since the carbonyl group is always at the end of the parent chain, no position number is needed.
Read more about aldehydes here
Ketones
Structure: Ketones contain a carbonyl functional group (C=O) bonded to two carbon atoms within the parent chain.
Nomenclature: Ketone names end with the suffix "-one" and use a prefix to indicate the number of carbon atoms in the parent chain (e.g., propanone, butanone, pentanone). The position of the carbonyl group is specified with a number before the name (e.g., 2-butanone, 3-pentanone). The position can also be denoted within the name (e.g., butan-2-one, pentan-3-one).
Carboxylic acids
Structure: Carboxylic acids contain a carboxyl functional group (COOH) bonded to a carbon atom.
Nomenclature: Carboxylic acid names end with the suffix "-oic acid" and use a prefix to indicate the number of carbon atoms in the parent chain (e.g., methanoic acid, ethanoic acid, propanoic acid). The carboxyl group is always at the end of the parent chain, so no position number is needed.
Read more about carboxylic acids here
Esters
Structure: Esters contain a carbonyl functional group (C=O) bonded to an alkyl group and an oxygen atom, which is bonded to another alkyl group (RCOOR').
Nomenclature: Ester names have two parts: the alkyl group bonded to the oxygen atom (R') and the parent chain containing the carbonyl group (RCOO-). The name of the alkyl group (R') is followed by the name of the parent chain, which ends with the suffix "-oate" (e.g., methyl ethanoate, ethyl propanoate).
Amines
Structure: Amines contain a nitrogen atom bonded to one, two, or three carbon atoms or hydrogen atoms.
Nomenclature: Amine names end with the suffix "-amine" and use a prefix to indicate the number of carbon atoms in the parent chain (e.g., methanamine, ethanamine, propanamine). The position of the nitrogen atom is specified with a number before the name (e.g., 1-propanamine) or within the name (e.g., propan-1-amine).
Amides
Structure: Amides contain a carbonyl functional group (C=O) bonded to a nitrogen atom, which can be bonded to hydrogen atoms or alkyl groups (RCONH2, RCONHR', RCONR'R'').
Nomenclature: Amide names end with the suffix "-amide" and use a prefix to indicate the number of carbon atoms in the parent chain (e.g., methanamide, ethanamide, propanamide). If the nitrogen atom is bonded to alkyl groups, they are named as substituents with the prefix "N-" before the alkyl group name (e.g., N-methylpropanamide).