Haloalkanes and Haloarenes Vocabulary Flashcards

Key vocabulary terms, definitions, named reactions, and classification mechanisms for Haloalkanes and Haloarenes chemistry.

Allylic halides

Compounds containing a halogen atom bonded to an $sp^3$ hybridised carbon atom next to a carbon-carbon double bond (e.g., $CH_2=CH-CH_2-Cl$).

Benzylic halides

Compounds containing a halogen atom bonded to an $sp^3$ hybridised carbon atom next to an aromatic ring.

Vinylic halides

Compounds containing a halogen atom bonded to an $sp^2$ hybridised carbon atom of an aliphatic compound (e.g., $CH_2=CH-Cl$).

Aryl halides

Compounds containing a halogen atom bonded to an $sp^2$ hybridised carbon atom of an aromatic ring.

Groove's process

The synthesis of chloroalkanes by treating an alcohol with $HCl$ in the presence of anhydrous $ZnCl_2$.

Darzen's Method

A reaction method to prepare alkyl chlorides by reacting primary alcohols with thionyl chloride ($SOCl_2$), where all side products ($SO_2$ and $HCl$) are gaseous.

Kharasch effect

The addition of $HBr$ to unsymmetrical alkenes in the presence of peroxides following anti-Markovnikov's rule.

Finkelstein Reaction

A halide exchange reaction in which an alkyl chloride or alkyl bromide is treated with $NaI$ in acetone to produce an alkyl iodide.

Swarts Reaction

A halide exchange process used to prepare alkyl fluorides by heating an alkyl chloride or bromide with metallic fluorides such as $AgF$, $Hg_2F_2$, $CoF_2$, or $SbF_3$.

Sandmeyer reaction

The synthesis of aryl chlorides or aryl bromides by treating a diazonium salt with $Cu_2Cl_2$ or $Cu_2Br_2$.

Gatterman reaction

The conversion of a diazonium salt into an aryl chloride or bromide using copper powder ($Cu$) and $HCl$ or $HBr$.

Ambident Nucleophiles

Nucleophiles that possess lone pairs of electrons on more than one atom and can attack a substrate through more than one site (e.g., $CN^-$ and $NO_2^-$).

Chirality

The property of non-superimposability of a molecule or object on its mirror image.

Enantiomers

Molecules that are non-superimposable mirror images of each other, possessing identical physical properties except for the direction of optical rotation.

Diastereomers

Stereoisomers that are not mirror images of each other and possess different physical and chemical properties.

Racemic Mixture

A 1:1 molar mixture of dextro and laevo forms of the same enantiomeric pair, which is optically inactive due to external compensation.

Racemization

The conversion of an optically active $(+)$ or $(-)$ isomer into its optically inactive racemic mixture ($\pm$).

Resolution

The process of separating a racemic mixture into its individual enantiomeric $d$ and $l$ forms.

$S_N2$ Mechanism

A single-step bimolecular nucleophilic substitution reaction involving a transition state with simultaneous nucleophilic attack and leaving group departure, resulting in inversion of configuration.

$S_N1$ Mechanism

A two-step unimolecular nucleophilic substitution reaction where slow ionisation forms a planar carbocation intermediate in the rate-determining step, leading to partial racemisation.

Saytzeff's rule

A rule stating that dehydrohalogenation of haloalkanes using alcoholic $KOH$ predominantly yields the more substituted alkene as the major product.

Wurtz Reaction

A reaction where two molecules of alkyl halide react with sodium metal in dry ether to form a higher alkane containing an even number of carbon atoms.

Fittig reaction

A reaction in which haloarenes are treated with sodium metal in dry ether to yield diarenes (diphenyl).

Wurtz-Fittig reaction

A reaction involving a mixture of an alkyl halide and an aryl halide treated with sodium metal in dry ether to yield an alkyl benzene.

Gem dihalides

Compounds containing two halogen atoms attached to the same carbon atom in a single molecule, also known as alkylidene dihalides.

Vicinal dihalides

Compounds containing two halogen atoms attached to adjacent carbon atoms, also known as alkylene dihalides.

Chloropicrin

A compound ($CCl_3NO_2$) formed by reacting chloroform ($CHCl_3$) with concentrated $HNO_3$, used primarily as an insecticide.

Carbylamine test

A chemical test where primary aliphatic or aromatic amines react with chloroform ($CHCl_3$) and alcoholic $KOH$ to form foul-smelling isocyanides.

Freons

Chlorofluorocarbon compounds derived from methane and ethane (e.g., Freon-12, $CCl_2F_2$) commonly used as refrigerants and air conditioning agents.

Pyrene

The commercial trade name for carbon tetrachloride ($CCl_4$) when utilized as a fire extinguisher.

Stereoselective reaction

A chemical reaction that generates a carbon-carbon double bond or chirality center resulting in the preferential formation of one stereoisomer over another.

Stereospecific reaction

A reaction in which stereoisomeric starting materials lead to different stereoisomeric products.

Hunsdiecker Reaction

The reaction of silver salts of carboxylic acids with $Br_2$ or $Cl_2$ in $CCl_4$ via a free radical mechanism to yield alkyl halides.

Ullmann Reaction

The thermal reaction of iodobenzene with copper powder to produce diphenyl ($C_6H_5-C_6H_5$) and copper(I) iodide ($Cu_2I_2$).