M1.3 Organic Chemistry

The study of compounds containing carbon, hydrogen, halogen, oxygen, nitrogen, sulfur, and phosphorus

Organic Chemistry

Organic compounds composed entirely of carbon and hydrogen that serve as the structural backbone

Hydrocarbons

Hydrocarbons that form chains or branches and can be either saturated or unsaturated

Aliphatic Hydrocarbons

Hydrocarbons containing benzene rings or fused polycyclic benzenoid systems

Aromatic Hydrocarbons

A polycyclic aromatic hydrocarbon made of two fused benzene rings

Naphthalene

A polycyclic aromatic hydrocarbon made of three linearly fused benzene rings whose derivatives serve as intercalating antineoplastic agents

Anthracene

A polycyclic aromatic hydrocarbon made of three angularly fused benzene rings, forming the cyclopentanoperhydrophenanthrene core

Phenanthrene

A polycyclic aromatic hydrocarbon made of four fused benzene rings in a specific angular structure

Chrysene

A polycyclic aromatic hydrocarbon consisting of four fused benzene rings forming a compact, symmetric cluster

Pyrene

The general notation used to represent an alkyl group substituent

R

The general notation used to represent an aryl or phenyl group substituent

Ar or Ph

Organic derivatives represented by the general structure R-X or Ar-X

Halides

Organic compounds containing a hydroxyl group attached to an aliphatic carbon chain (R-OH)

Alcohols

Organic compounds containing a hydroxyl group directly attached to a benzene ring (Ph-OH)

Phenols

Organic molecules where an oxygen atom is sandwiched between two hydrocarbon groups (R-O-R)

Ethers

Carbonyl compounds containing at least one hydrogen atom attached to the carbonyl carbon (RCHO)

Aldehydes

Carbonyl compounds where the carbonyl carbon is bonded to two hydrocarbon groups (RCOR)

Ketones

Compounds characterized by a carboxyl group attached to a hydrogen or hydrocarbon group (RCOOH)

Carboxylic Acid

A carboxylic acid derivative formed by replacing the hydroxyl group with an alkoxy group (RCOOR)

Ester

An organic derivative of ammonia where one hydrocarbon group is attached to the nitrogen atom

Primary Amine

An organic derivative of ammonia where two hydrocarbon groups are attached to the nitrogen atom

Secondary Amine

An organic derivative of ammonia where three hydrocarbon groups are attached to the nitrogen atom

Tertiary Amine

A positively charged nitrogen compound bonded to four distinct hydrocarbon groups

Quaternary Ammonium

Organic sulfur compounds containing a sulfhydryl group attached to a carbon chain (R-SH)

Thiols

Organic compounds where a sulfur atom is sandwiched between two hydrocarbon groups (R-S-R)

Thioethers

Carboxylic acid derivatives where the acyl carbon is bonded to a sulfur group (R-CO-S-R)

Thioesters

A fused heterocyclic ring system consisting of a benzene ring and a pyrimidine ring

Quinazoline

A five-membered heterocyclic ring system containing two non-adjacent nitrogen atoms

Imidazole

A six-membered heterocyclic ring system containing two nitrogen atoms located at positions 1 and 3

Pyrimidine

A five-membered heterocyclic ring containing four nitrogen atoms

Tetrazole

A five-membered heterocyclic ring containing exactly one nitrogen atom

Pyrrole

The structural rule stating that atoms lose, gain, or share electrons to achieve a stable outer shell of eight electrons

Octet Rule

The unique ability of carbon atoms to form multiple stable covalent bonds with themselves to create long chains or rings

Catenation

The process of mixing non-equivalent atomic orbitals to form a new set of equivalent orbitals for covalent bonding

Hybridization

The hybrid orbital type characterized by a linear geometry and an AB2 formula structure

sp Hybrid orbital

The hybrid orbital type characterized by a trigonal planar geometry and an AB3 formula structure

sp2 Hybrid orbital

The hybrid orbital type characterized by a tetrahedral geometry and an AB4 formula structure

sp3 Hybrid orbital

The phenomenon where two or more compounds share the same molecular formula but have different structural connectivity or arrangements

Isomerism

Isomers that share the same molecular formula but differ fundamentally in the bonding order or connectivity of their atoms

Structural / Constitutional Isomers

A type of structural isomerism exhibited by alkanes due to differences in carbon chain branching

Chain Isomerism

Structural isomers that differ in the specific location of a multiple bond or functional group on the exact same carbon backbone

Positional Isomers

A classical benzene substitution position designating a 1,2-disubstituted relationship on the ring

Ortho (o)

A classical benzene substitution position designating a 1,3-disubstituted relationship on the ring

Meta (m)

A classical benzene substitution position designating a 1,4-disubstituted relationship on the ring

Para (p)

Structural isomers that share the same molecular formula but contain completely different functional groups

Functional Isomers

A mathematical calculation used to determine the total number of pi bonds and rings in a molecular structure

Index of Hydrogen Deficiency (IHD)

Isomers that possess the same molecular connectivity but differ strictly in the three-dimensional spatial orientation of their atoms

Stereoisomers

Stereoisomers that occur due to restricted rotation about double bonds or cyclic ring systems, including cis/trans forms

Geometric Isomers

The geometric isomer configuration where identical or high-priority groups reside on the exact same side of a reference plane

Cis Isomer

The geometric isomer configuration where identical or high-priority groups reside on opposite sides of a reference plane, offering greater stability

Trans Isomer

The priority rules based on atomic numbers used to determine configurations in the E/Z and R/S naming systems

Cahn-Ingold-Prelog Sequence

The geometric isomer designation used when high-priority groups are on the same side of a double bond

Z (Zame side)

The geometric isomer designation used when high-priority groups are on opposite sides of a double bond

E (Entgegen)

Stereoisomers produced by continuous rotation around single carbon-carbon sigma bonds

Conformational Isomers

A two-dimensional projection used to analyze conformational isomers by viewing directly down a single carbon-carbon bond axis

Newman Projection

The least stable conformation of a molecule where adjacent bonds or groups align directly behind each other, causing maximum repulsion

Eclipsed Conformation

The most stable conformation of a molecule where adjacent bonds or groups alternate to maximize distance between each other

Staggered Conformation

The potential energy penalty caused by a molecule resisting rotation away from an eclipsed conformation

Torsional Energy

The destabilizing physical crowding effect that occurs when bulky groups are forced close together in space

Steric Effect

The most stable conformation of butane where the two large methyl groups are separated by a dihedral angle of 180 degrees

Anti-staggered Conformation

The staggered conformation of butane where the two methyl groups are separated by a dihedral angle of 60 degrees

Gauche Conformation

A highly strained cyclic alkane that features bent "banana bonds" due to severe angle strain

Cyclopropane

A four-membered cyclic alkane that adopts a puckered "butterfly" conformation to reduce eclipsing strain

Cyclobutane

A five-membered cyclic alkane that primarily adopts "envelope" or "half-chair" conformations to minimize strain

Cyclopentane

The most stable conformation of cyclohexane because it completely eliminates angle strain, eclipsing strain, and steric crowding

Chair Conformation

The high-energy conformation of cyclohexane that suffers from eclipsing strain at two bonds and significant flagpole interactions

Boat Conformation

The property of a chemical compound that allows it to rotate the plane of polarized light in a polarimeter

Optical Activity

An optical isomer that rotates plane-polarized light to the right or clockwise direction

Dextrorotatory (d / +)

An optical isomer that rotates plane-polarized light to the left or counterclockwise direction

Levorotatory (l / -)

An sp3 hybridized carbon atom bonded to four entirely unique and distinct chemical groups

Chiral Center

Stereoisomers that are non-superimposable mirror images of each other, sharing identical physical properties except for light rotation

Enantiomers

Stereoisomers that contain chiral centers but are not mirror images of one another

Diastereomers

An optically inactive molecule that contains chiral centers but also possesses an internal plane of symmetry

Meso Compound

An optically inactive 50:50 mixture containing equal concentrations of opposite enantiomers, resulting in external compensation

Racemic Mixture

A historic sedative drug whose R-enantiomer is effective against morning sickness while its S-enantiomer is highly teratogenic

Thalidomide

The absolute configuration assigned when priority groups rotate in a clockwise direction with the lowest priority group at the back

R Configuration

The absolute configuration assigned when priority groups rotate in a counterclockwise direction with the lowest priority group at the back

S Configuration

The complete oxidation reaction of an alkane in the presence of excess oxygen to yield carbon dioxide and water

Complete Combustion

The chemical process in which alkanes react with halogens via a free radical pathway initiated by ultraviolet light or heat

Halogenation

The initial step of free radical substitution where homolytic cleavage of a molecule occurs to generate reactive radicals

Initiation

The continuous step of free radical substitution characterized by having a radical species on both sides of the reaction equation

Propagation

The final step of free radical substitution where two radicals combine to form a stable covalent molecule

Termination

The primary mechanism driving alkene reactivity, involving the addition of components across a weaker pi bond

Electrophilic Addition

The industrial reduction process where hydrogen gas is added across a double bond using a metal catalyst like Pt, Pd, or Ni

Catalytic Hydrogenation

The specific addition reaction of an alkene with chlorine or bromine to produce a vicinal dihalide

Halogenation of Alkenes

The rule stating that in the addition of HX to an alkene, the hydrogen adds to the carbon with more hydrogen atoms to form a more stable carbocation

Markovnikov's Rule

An organic test that uses a cold, alkaline solution of potassium permanganate to identify unsaturation via the formation of a brown precipitate

Baeyer's Test

The oxidation reaction of alkenes with oxygen over a silver oxide catalyst to form three-membered cyclic ethers called oxiranes

Epoxidation

A catalyst composed of palladium on calcium carbonate treated with lead, used to selectively reduce alkynes to cis-alkenes

Lindlar Catalyst

The equilibrium process where an unstable enol intermediate produced by alkyne hydration rapidly converts into a stable carbonyl compound

Tautomerization

The rule defining aromaticity, stating that a planar, cyclic, completely conjugated system must contain 4n+2 pi electrons

Huckel's Rule

A compound that is cyclic, planar, and completely conjugated but contains 4n pi electrons, making it highly unstable

Antiaromatic Compound

The dominant reaction mechanism of aromatic rings, which allows the system to undergo substitution while preserving its resonance stability

Electrophilic Aromatic Substitution (EAS)

An aromatic substitution reaction that utilizes concentrated nitric acid and sulfuric acid to generate a nitronium ion electrophile

Nitration

An aromatic substitution reaction that introduces an alkyl group onto a benzene ring using an alkyl halide and a Lewis acid catalyst

Friedel-Crafts Alkylation

An aromatic substitution reaction that introduces an acyl group onto a benzene ring via a stable acylium ion intermediate

Friedel-Crafts Acylation

Benzene substituents like amino or hydroxyl groups that increase electron density on the ring and direct incoming electrophiles to positions 2 and 4

Ortho/Para Directing Activators

Benzene substituents like nitro or cyano groups that decrease electron density on the ring and direct incoming electrophiles to position 3

Meta Directing Deactivators

Deactivating substituents on a benzene ring that paradoxically direct incoming electrophiles to the ortho and para positions due to lone pair resonance

Halogens

An alcohol classification determined by the hydroxyl group being bound to a carbon attached to only one other carbon atom

Primary Alcohol