Organic compounds can be represented by different types of formulas. These include empirical, molecular, structural (full and condensed), stereochemical and skeletal.
Identify different formulas and interconvert molecular, skeletal and structural formulas.
Construct 3D models (real or virtual) of organic molecules.
Stereochemical formulas are not expected to be drawn, except where specifically indicated.
Functional groups give characteristic physical and chemical properties to a compound. Organic compounds are divided into classes according to the functional groups present in their molecules.
Identify the following functional groups by name and structure: halogeno, hydroxyl, carbonyl, carboxyl, alkoxy, amino, amido, ester, phenyl.
The terms “saturated” and “unsaturated” should be included.
A homologous series is a family of compounds in which successive members differ by a common structural unit, typically CH2. Each homologous series can be described by a general formula.
Identify the following homologous series: alkanes, alkenes, alkynes, halogenoalkanes, alcohols, aldehydes, ketones, carboxylic acids, ethers, amines, amides and esters.
Successive members of a homologous series show a trend in physical properties.
Describe and explain the trend in melting and boiling points of members of a homologous series.
“IUPAC nomenclature” refers to a set of rules used by the International Union of Pure and Applied Chemistry to apply systematic names to organic and inorganic compounds.
Apply IUPAC nomenclature to saturated or mono-unsaturated compounds that have up to six carbon atoms in the parent chain and contain one type of the following functional groups: halogeno, hydroxyl, carbonyl, carboxyl.
Include straight-chain and branched-chain isomers.
Structural isomers are molecules that have the same molecular formula but different connectivities.
Recognize isomers, including branched, straight-chain, position and functional group isomers.
Primary, secondary and tertiary alcohols, halogenoalkanes and amines should be included.
Stereoisomers have the same constitution (atom identities, connectivities and bond multiplicities) but different spatial arrangements of atoms.
Describe and explain the features that give rise to cis-trans isomerism; recognize it in non-cyclic alkenes and C3 and C4 cycloalkanes.
Draw stereochemical formulas showing the tetrahedral arrangement around a chiral carbon.
Describe and explain a chiral carbon atom giving rise to stereoisomers with different optical properties.
Recognize a pair of enantiomers as non-superimposable mirror images from 3D modelling (real or virtual).
Nomenclature using the E‐Z system will not be assessed.
The terms “chiral”, “optical activity”, “enantiomer” and “racemic” mixture should be understood.
Knowledge of the different chemical properties of enantiomers can be limited to the fact that they behave differently in chiral environments.
Wedge-dash type representations involving tapered bonds should be used for the representation of enantiomers.
Mass spectrometry (MS) of organic compounds can cause fragmentation of molecules.
Deduce information about the structural features of a compound from specific MS fragmentation patterns.
Include reference to the molecular ion.
Data on specific MS fragments are provided in the data booklet.
Infrared (IR) spectra can be used to identify the type of bond present in a molecule.
Interpret the functional group region of an IR spectrum, using a table of characteristic frequencies (wavenumber/cm-1).
Include reference to the absorption of IR radiation by greenhouse gases.
Data for interpretation of IR spectra are given in the data booklet.
Proton nuclear magnetic resonance spectroscopy (1H NMR) gives information on the different chemical environments of hydrogen atoms in a molecule.
Interpret 1H NMR spectra to deduce the structures of organic molecules from the number of signals, the chemical shifts, and the relative areas under signals (integration traces).
Individual signals can be split into clusters of peaks.
Interpret 1H NMR spectra from splitting patterns showing singlets, doublets, triplets and quartets to deduce greater structural detail.
Data for interpretation of 1H NMR spectra are given in the data booklet.
Data from different techniques are often combined in structural analysis.
Interpret a variety of data, including analytical spectra, to determine the structure of a molecule.