Haloalkanes and Haloarenes

Vocabulary flashcards derived from the lecture on Haloalkanes and Haloarenes, covering chemical classifications, major name reactions, stereochemical terminology, and environmental impacts of polyhalogen compounds.

Haloalkanes

Organic compounds in which halogen atom(s) are attached to the $sp^3$ hybridised carbon atom of an alkyl group.

Haloarenes

Organic compounds in which halogen atom(s) are attached to $sp^2$ hybridised carbon atom(s) of an aryl group.

Chloramphenicol

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

Thyroxine

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

Chloroquine

A synthetic halogen 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 to an aromatic ring.

Vinylic halides

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

Aryl halides

Compounds in which the halogen atom is directly bonded to the $sp^2$-hybridised carbon atom of an aromatic ring.

Geminal halides (gem-dihalides)

Dihaloalkanes in which both halogen atoms are present on the same carbon atom of the chain.

Vicinal halides (vic-dihalides)

Dihaloalkanes in which the halogen atoms are present on adjacent carbon atoms.

Finkelstein reaction

The synthesis of alkyl iodides by the reaction of alkyl chlorides or bromides with $NaI$ in dry acetone.

Swarts reaction

The synthesis of alkyl fluorides by heating an alkyl chloride or bromide in the presence of a metallic fluoride such as $AgF$, $Hg_2F_2$, $CoF_2$, or $SbF_3$.

Sandmeyer’s reaction

The replacement of a diazonium group in a freshly prepared diazonium salt with $-Cl$ or $-Br$ using cuprous chloride or cuprous bromide.

$S_N2$ reaction

A substitution nucleophilic bimolecular reaction that follows second order kinetics and occurs in a single step with inversion of configuration.

Inversion of configuration

A process in which the spatial arrangement of the carbon atom under attack inverts, similar to an umbrella being turned inside out.

$S_N1$ reaction

A substitution nucleophilic unimolecular reaction that follows first order kinetics and occurs in two steps via a carbocation intermediate.

Chiral

Objects or molecules which are non-superimposable on their mirror image.

Enantiomers

Stereoisomers related to each other as non-superimposable mirror images that possess identical physical properties except for the direction of optical rotation.

Racemic mixture

A mixture containing two enantiomers in equal proportions, resulting in zero optical rotation.

Zaitsev rule

In dehydrohalogenation reactions, the preferred product is that alkene which has the greater number of alkyl groups attached to the doubly bonded carbon atoms.

Grignard Reagents

Organo-metallic compounds with the general formula $RMgX$ formed by the reaction of haloalkanes with magnesium metal in dry ether.

Wurtz reaction

The reaction of alkyl halides with sodium in dry ether to give hydrocarbons containing double the number of carbon atoms present in the halide.

Phosgene

A poisonous gas, also known as carbonyl chloride ($COCl_2$), formed by the slow oxidation of chloroform by air in the presence of light.

Freons

Extremely stable, unreactive, non-toxic, and non-corrosive chlorofluorocarbon compounds of methane and ethane used as aerosol propellants and refrigerants.

DDT

$p,p'-Dichlorodiphenyltrichloroethane$, the first chlorinated organic insecticide, originally prepared in 1873.