Haloalkanes and Haloarenes Review

A set of vocabulary flashcards based on lecture notes covering the classification, preparation, nomenclature, and chemical reactions of haloalkanes and haloarenes.

Haloalkanes

Hydrocarbons in which one or more hydrogen atoms are replaced by halogen atoms attached to an $sp^3$ hybridised carbon atom of an alkyl group.

Haloarenes

Compounds formed by the replacement of hydrogen atoms in aromatic hydrocarbons by halogen atoms attached to $sp^2$ hybridised carbon atoms.

Chloramphenicol

A chlorine-containing antibiotic produced by microorganisms that is effective against typhoid fever.

Thyroxine

An iodine-containing hormone produced by the human body; its deficiency leads to the disease known as goiter.

Chloroquine

A synthetic halogenated compound used as a pharmaceutical treatment for malaria.

Halothane

A halogen-based compound utilized as an anaesthetic during surgical operations.

Allylic halides

Compounds where a halogen atom is bonded to an $sp^3$ hybridised carbon atom that is 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 that is directly attached to an aromatic ring.

Vinylic halides

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

Aryl halides

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

Geminal halides

Dihaloalkanes where both halogen atoms are attached to the same carbon atom, also known as alkylidene halides.

Vicinal halides

Dihaloalkanes where the halogen atoms are attached to adjacent carbon atoms, also referred to as alkylene dihalides.

Thionyl chloride

A reagent ($SOCl_2$) used to prepare alkyl halides from alcohols; it is preferred because the by-products $SO_2$ and $HCl$ are escapable gases.

Finkelstein reaction

A halogen exchange method for preparing alkyl iodides by reacting alkyl chlorides or bromides with $NaI$ in dry acetone.

Swarts reaction

A reaction for synthesizing alkyl fluorides by heating alkyl chlorides or bromides with metallic fluorides such as $AgF$, $Hg_2F_2$, $CoF_2$, or $SbF_3$.

Sandmeyer’s reaction

A process where a freshly prepared diazonium salt is mixed with cuprous chloride or cuprous bromide to replace the diazonium group with $-Cl$ or $-Br$.

Optical activity

The ability of certain compounds to rotate the plane of plane-polarised light, measured using a polarimeter.

Chirality

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

Enantiomers

Stereoisomers that are non-superimposable mirror images of each other, possessing identical physical properties but rotating light in opposite directions.

Racemic mixture

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

$SN2$ reaction

A bimolecular nucleophilic substitution characterized by a single-step mechanism, second order kinetics, and inversion of configuration.

$SN1$ reaction

A unimolecular nucleophilic substitution proceeding through a carbocation intermediate in two steps, often resulting in racemisation.

Zaitsev rule

A principle stating that in dehydrohalogenation reactions, the preferred product is the alkene with the greatest number of alkyl groups attached to the doubly bonded carbons.

Grignard Reagents

Organometallic compounds ($RMgX$) produced by reacting haloalkanes with magnesium metal in dry ether.

Wurtz reaction

An organic reaction where alkyl halides react with sodium in dry ether to form hydrocarbons with double the original carbon content.

Ambident nucleophiles

Nucleophiles that can link through two different atoms, such as the cyanide group which can bind through carbon to form nitriles or nitrogen to form isocyanides.

Phosgene

A highly poisonous gas ($COCl_2$) formed by the slow oxidation of chloroform in the presence of air and light.

Freons

Chlorofluorocarbon compounds of methane and ethane that are stable and non-toxic but contribute to ozone layer depletion.

DDT

A chlorinated organic insecticide ($p,p'\text{-Dichlorodiphenyltrichloroethane}$) that was the first of its kind, utilized for controlling malaria and typhus.