Haloalkanes and Haloarenes - Key Vocabulary Flashcards

Vocabulary flashcards generated from the Class 12 Haloalkanes and Haloarenes chemistry lecture notes covering classifications, mechanisms, reactions, and rules.

Geminal Dihalide

A dihalide in which both halogen atoms are attached to the exact same carbon atom.

Vicinal Dihalide

A dihalide in which both halogen atoms are attached to two adjacent carbon atoms.

Alkyl Halide

A organic compound in which a halogen atom is attached to an $sp^3$ hybridized carbon of an aliphatic chain.

Benzylic Halide

A compound in which a halogen atom is attached to an $sp^3$ hybridized carbon that is directly attached to a benzene ring.

Allylic Halide

A compound in which a halogen atom is attached to an $sp^3$ hybridized carbon that is directly attached to a carbon-carbon double bond.

Vinylic Halide

A compound in which a halogen atom is attached to an $sp^2$ hybridized carbon of a non-aromatic carbon skeleton.

Aryl Halide

A compound in which a halogen atom is attached to an $sp^2$ hybridized carbon of an aromatic benzene skeleton.

Alkynyl Halide

A compound in which a halogen atom is attached to an $sp$ hybridized carbon of an aliphatic chain.

Dipole Moment Order of Methyl Halides

The experimental dipole moment trend for methyl halides: $CH_3\text{-}Cl > CH_3\text{-}F > CH_3\text{-}Br > CH_3\text{-}I$.

Nucleophile

An electron-donor or electron-rich species that attacks electron-deficient centers, such as $OH^-$, $CN^-$, $Cl^-$, or $Br^-$.

Electrophile

An electron-acceptor or electron-loving species, such as $NO_2^+$, $H^+$, $AlCl_3$, or $BF_3$.

Ambident Nucleophile

Nucleophiles that possess two nucleophilic centers capable of donor attachment, such as cyanides and nitrites.

S_N1 Mechanism

A two-step substitution reaction with molecularity of 1, proceeding via a carbocation intermediate, allowing rearrangements, favored by weak nucleophiles/polar protic solvents, and leading to racemisation.

S_N2 Mechanism

A one-step substitution reaction with molecularity of 2, forming a transition state without carbocation rearrangement, requiring strong nucleophiles/polar aprotic solvents, and leading to inversion of configuration.

Optical Activity

The ability of a substance (in pure form or in solution) to rotate the plane of plane-polarized light.

Dextrorotatory

An optically active substance that rotates the plane of plane-polarized light in a clockwise direction, designated as $(+)$.

Levorotatory

An optically active substance that rotates the plane of plane-polarized light in an anti-clockwise direction, designated as $(-)$.

Enantiomer

Optical isomers that are non-superimposable mirror images of each other and rotate plane-polarized light in equal and opposite directions.

Asymmetric Carbon Atom (Chiral Atom)

A carbon atom bonded to four different atoms or distinct groups.

Lucas Reagent

A $1:1$ mixture of anhydrous $ZnCl_2$ and concentrated $HCl$, used to distinguish primary, secondary, and tertiary alcohols based on the speed of turbidity formation.

Swarts Reaction

A halogen exchange reaction used to synthesize alkyl fluorides by reacting alkyl halides (e.g., $CH_3Br$) with metallic fluorides like $AgF$.

Finkelstein Reaction

A halogen exchange reaction used to synthesize alkyl iodides by reacting alkyl halides with sodium iodide ($NaI$).

Anti-Markownikoff's Rule (Peroxide Effect)

The addition of $HBr$ to unsymmetrical alkenes in the presence of peroxide, heat, or light, causing the halogen to attach to the carbon with more hydrogen atoms.

Saytzeff Rule

In $\beta$-elimination (dehydrohalogenation) reactions, hydrogen is preferentially eliminated from the $\beta$-carbon having fewer hydrogen atoms to yield the more stable alkene.

Grignard Reagent

An organo-metallic compound of the form $RMgX$ (alkyl magnesium halide), discovered by Victor Grignard in 1900.

Wurtz Reaction

A reaction in which alkyl halides react with sodium metal in dry ether to yield hydrocarbons containing twice the original number of carbon atoms.