Unit 6: Haloalkanes and Haloarenes

Vocabulary practice flashcards covering nomenclature, classification, reactions, stereochemistry, and polyhalogen compounds from Unit 6: Haloalkanes and Haloarenes.

Haloalkanes

Aliphatic hydrocarbons in which one or more hydrogen atoms are replaced by halogen atoms, containing the halogen attached to an $sp^3$ hybridised carbon atom.

Haloarenes

Aromatic hydrocarbons in which one or more hydrogen atoms are replaced by halogen atoms, containing the halogen directly attached to an $sp^2$ hybridised carbon atom of an aryl ring.

Chloramphenicol

A chlorine-containing antibiotic produced by microorganisms that is effective for the treatment of typhoid fever.

Thyroxine

An iodine-containing hormone produced by the human body, the deficiency of which causes goiter.

Chloroquine

A synthetic halogen-containing compound used for the treatment of malaria.

Halothane

A synthetic halogen compound used as an anaesthetic during surgery.

Allylic halides

Compounds in which the halogen atom is bonded to an $sp^3$-hybridised carbon atom adjacent to a carbon-carbon double bond ($C=C$).

Benzylic halides

Compounds in which the halogen atom is bonded to an $sp^3$-hybridised carbon atom attached directly to an aromatic ring.

Vinylic halides

Compounds in which the halogen atom is bonded directly to an $sp^2$-hybridised carbon atom of a carbon-carbon double bond ($C=C$).

Geminal halides (gem-dihalides)

Dihaloalkanes having both halogen atoms bonded to the same carbon atom of the chain, commonly named as alkylidene halides.

Vicinal halides (vic-dihalides)

Dihaloalkanes having halogen atoms bonded to adjacent carbon atoms, commonly named as alkylene dihalides.

Finkelstein reaction

A halogen exchange reaction in which alkyl chlorides or bromides are treated with $\text{NaI}$ in dry acetone to produce alkyl iodides.

Swarts reaction

The synthesis of alkyl fluorides accomplished by heating an alkyl chloride or bromide in the presence of a metallic fluoride such as $\text{AgF}$, $\text{Hg}_2\text{F}_2$, $\text{CoF}_2$, or $\text{SbF}_3$.

Sandmeyer's reaction

A reaction where freshly prepared benzene diazonium halide is treated with cuprous chloride ($\text{Cu}_2\text{Cl}_2$) or cuprous bromide ($\text{Cu}_2\text{Br}_2$) to replace the diazonium group with $-Cl$ or $-Br$.

Ambident nucleophiles

Species possessing two nucleophilic centres that can attack a substrate through either of two different atoms (such as cyanide and nitrite ions).

Inversion of configuration

A stereochemical transformation occurring during $\text{S}_\text{N}2$ reactions where the relative spatial arrangement of substituents about a carbon atom turns inside out (like an umbrella in a wind storm).

Retention of configuration

The preservation of the spatial arrangement of bonds to an asymmetric stereocentre during a chemical transformation without breaking bonds directly to that centre.

Chirality

The property of an object or molecule of being non-superimposable on its mirror image.

Enantiomers

Optical stereoisomers that are non-superimposable mirror images of each other and rotate plane polarised light by equal magnitudes in opposite directions.

Racemic mixture

An equimolar mixture containing two enantiomers in equal proportions, resulting in zero net optical rotation.

Zaitsev's rule

A dehydrohalogenation rule stating that the preferred major product is the alkene having the greater number of alkyl groups attached to the doubly bonded carbon atoms.

Grignard reagents

Organomagnesium halides with the general formula $\text{RMgX}$, prepared by the reaction of haloalkanes with magnesium metal in dry ether.

Wurtz reaction

The reaction of alkyl halides with sodium in dry ether to yield symmetrical alkanes containing double the number of carbon atoms present in the starting halide.

Wurtz-Fittig reaction

The reaction of an equimolar mixture of an alkyl halide and an aryl halide with sodium in dry ether to yield an alkylarene.

Fittig reaction

The reaction of aryl halides with sodium in dry ether to yield biaryl compounds where two aryl groups are joined together.

Freons

Chlorofluorocarbon compounds of methane and ethane that are extremely stable, unreactive, non-toxic, non-corrosive, easily liquefiable gases used as refrigerants and propellants.

DDT

p,p'-Dichlorodiphenyltrichloroethane, a chlorinated organic insecticide originally prepared in 1873 whose insecticidal properties were discovered by Paul Müller in 1939.