Organic Chemistry — 60 Terms Defined

Alcohol Organic Chemistry Dimensionless An organic compound containing a hydroxyl group bonded to a saturated carbon atom. R–OH

Aldehyde Organic Chemistry Dimensionless A compound containing a carbonyl group bonded to at least one hydrogen atom, so it lies at the end of a chain. R–CHO

Aldol Condensation Organic Chemistry Dimensionless The base-catalysed reaction of two carbonyl compounds to give a beta-hydroxy carbonyl, which often dehydrates to an enone. 2RCH₂CHO → RCH₂CH(OH)CHRCHO

Alkane Organic Chemistry Dimensionless A saturated hydrocarbon containing only single carbon–carbon bonds. CₙH₂ₙ₊₂

Alkene Organic Chemistry Dimensionless An unsaturated hydrocarbon containing at least one carbon–carbon double bond. CₙH₂ₙ

Alkyne Organic Chemistry Dimensionless An unsaturated hydrocarbon containing at least one carbon–carbon triple bond. CₙH₂ₙ₋₂

Amide Organic Chemistry Dimensionless A compound in which a carbonyl group is bonded directly to nitrogen. R–CO–NH₂

Amine Organic Chemistry Dimensionless A compound derived from ammonia by replacing one or more hydrogens with alkyl or aryl groups. R–NH₂, R₂NH, R₃N

Anti-Markovnikov Addition Organic Chemistry Dimensionless Addition in which the hydrogen attaches to the carbon bearing fewer hydrogens, reversing the normal regiochemistry.

Arene Organic Chemistry Dimensionless An aromatic hydrocarbon containing one or more benzene rings. CₙH₂ₙ₋₆

Aromaticity Organic Chemistry kJ/mol The special stability of planar cyclic molecules with a continuous, fully conjugated system of delocalised pi electrons. planar, cyclic, conjugated, 4n+2 π

Benzene Organic Chemistry Dimensionless The simplest aromatic hydrocarbon, a planar regular hexagon of six sp² carbons with a delocalised pi cloud. C₆H₆

Cannizzaro Reaction Organic Chemistry Dimensionless The disproportionation of an aldehyde with no alpha hydrogen under concentrated alkali into an alcohol and a carboxylate. 2RCHO + OH⁻ → RCH₂OH + RCOO⁻

Carbanion Organic Chemistry Dimensionless An organic ion in which a carbon atom bears a negative charge and a lone pair. R₃C⁻

Carbocation Organic Chemistry Dimensionless An organic ion in which a carbon atom bears a positive charge and only six valence electrons. R₃C⁺

Carboxylic Acid Organic Chemistry Dimensionless A compound containing a carboxyl group, in which a carbonyl and a hydroxyl group share the same carbon. R–COOH

Chain Isomerism Organic Chemistry Dimensionless Structural isomerism arising from different arrangements of the carbon skeleton.

Chirality Organic Chemistry Dimensionless The property of a molecule that makes it non-superimposable on its mirror image.

Conformational Isomerism Organic Chemistry kJ/mol The different spatial arrangements a molecule can adopt through rotation about single bonds.

Diastereomer Organic Chemistry Dimensionless A stereoisomer that is not a mirror image of the compound with which it is compared.

E1 Reaction Organic Chemistry s⁻¹ A two-step elimination proceeding through a carbocation, which then loses a proton to form an alkene. rate = k[substrate]

E2 Reaction Organic Chemistry L/(mol·s) A single-step elimination in which a base removes a proton as the leaving group departs, forming a double bond. rate = k[substrate][base]

Electrophile Organic Chemistry Dimensionless An electron-deficient species that seeks and accepts a pair of electrons from an electron-rich centre. E⁺

Electrophilic Addition Organic Chemistry Dimensionless A reaction in which an electrophile adds across a carbon–carbon multiple bond, converting a pi bond into two sigma bonds. C=C + E–Nu → C(E)–C(Nu)