Organic Chemistry and Instrumental Analysis

**Organic Chemistry and Instrumental Analysis** is the second unit within the Advanced Higher Chemistry course. It consists of six subtopics; Molecular orbitals, Molecular structure, Stereo chemistry, Synthesis, Experimental determination of structure and Pharmaceutical chemistry.

## Subtopics

### Molecular orbitals

* Formation of bonding molecular orbitals.
* Hybridisation sp3, sp2 hybrid orbitals and their role in the formation of sigma and pi bonds.
* The symmetry and position of bonding orbitals between atoms determines types of bonding Ionic, polar and non-polar covalent bonding.
* Absorption of visible light by organic molecules.
* An explanation of why organic compounds are colourless or coloured with reference to molecular orbital theory including HOMO and LUMO or conjugated systems.
* Describe a Chromophore and explain its role in the colour exhibited by the compound.

### Molecular structure

* Draw and convert between molecular, structural and skeletal formulae with no more than 10 carbon atoms in their longest chain.

### Stereo chemistry

* Stereoisomerism
* Geometric isomerism.
* *cis* and *trans*. Physical and chemical properties of geometric isomers
* Optical isomerism.
* Non-superimposable mirror image, chiral/enantiomers. Racemic mixture and effect on polarised light.
* Physical and chemical properties of optical isomers.

### Synthesis

* From given equations identify: substitution, addition, elimination, condensation, hydrolysis, oxidation, reduction reactions.
* Devise synthetic routes, with no more than three steps, from a given reactant to a final product.
* Deduce possible reactions from molecular structures.
* Homolytic and heterolytic fission.
* Electrophiles and Nucleophiles.
* Reactions involving heterolytic bond fission. Nucleophiles or electrophiles as attacking groups.
* Use of double-headed, single-headed and curly arrows to show electron movement.
* Haloalkanes
* Classification of monohaloalkanes as primary, secondary or tertiary.
* Monohaloalkanes undergo nucleophilic substitution reactions:
	1. alkalis to form alcohols
	2. alcoholic alkoxides to form ethers
	3. ethanolic cyanide to form nitriles which can be hydrolysed to carboxylic acids
* Monohaloalkanes- elimination reactions to form alkenes.
* The reaction mechanism for SN1 and SN2 reactions and associated factors.
* SN1 and SN2 reactions using curly arrows and mechanisms with particular attention given to the transition state/intermediate.
* Alcohols
* The preparation properties and reactions of alcohols.
* Preparation from alkenes, haloalkanes and reduction of carbonyl compounds using lithium aluminium hydride.
* Physical properties related to bonding.
* Dehydration, reaction with metals, reactions with carboxylic acids and acid chlorides.

* Ethers
* Naming and general structure. Boiling point related to bonding. Preparation using haloalkanes with alkoxides. Chemical and physical properties of ethers linked to molecular size and uses.
* Alkenes
* Preparation:
	1. dehydration of alcohols
	2. base-induced elimination of hydrogen halides from monohaloalkanes
* Electrophilic addition reactions:
	1. catalytic addition of hydrogen to form alkanes
	2. Including mechanisms for addition of halogens to form dihaloalkanes
	3. addition of hydrogen halides according to Markovnikov’s rule, to form monohaloalkanes
	4. acid-catalysed addition of water according to Markovnikov’s rule, to form alcohols

* Carboxylic acids

Preparation by:

* 1. oxidising primary alcohols and aldehydes
	2. hydrolysing nitriles, esters, amides
* Reactions:
	1. formation of salts by reactions with metals or bases
	2. condensation reactions with alcohols to form esters in the presence of an acid catalyst
	3. reaction with amino groups to form amide links
	4. reduction with lithium aluminium hydride to form primary alcohols
* Amine
* Classification as primary, secondary or tertiary.
* Physical properties related to structure.
* Amines as weak bases and their use in salt formation.
* Aromatic hydrocarbons
* Aromatic hydrocarbons and reactions of benzene.
* Structure, bonding and stability of the benzene ring. Substitution reactions of benzene (phenyl); alkylation, nitration, sulfonation and halogenation as examples of electrophilic substitution in benzene and other aromatic compounds.

### Experimental determination of structure

* Elemental microanalysis
* Determination of the masses of C, H, O, S and N in a sample of an organic compound in order to determine its empirical formula.
* Mass spectrometry
* Interpretation of fragmentation data from mass spectra to gain structural information.
* Infra-red spectroscopy
* Interpretation of spectral data from IR to gain structural information.
* 1H NMR
* Interpretation of 1H NMR spectra.
* Interpretation of spectral data to gain structural information.
* Draw and analyse low resolution proton NMR spectra and to analyse high resolution proton NMR spectra.

### Pharmaceutical chemistry

* Effect of drugs on the body.
* Classification of drugs as agonists or as antagonists.
* How drugs work.
* Identify the types of interaction between drug functional groups and receptor sites.
* Recognise the active structural fragments in drug molecules which confer pharmacological activity
* % solution by mass, % solution by volume and ppm, calculations.