Organic Chemistry and Molecular Geometry Review

Comprehensive vocabulary flashcards covering organic chemistry nomenclature, carbocation stability, molecular geometry, reaction types SN1/SN2/E1/E2, and stereoisomerism.

Meth-

Nomenclature prefix indicating a 1-carbon chain.

Eth-

Nomenclature prefix indicating a 2-carbon chain.

Prop-

Nomenclature prefix indicating a 3-carbon chain.

But-

Nomenclature prefix indicating a 4-carbon chain.

Carbocation Stability

The relative stability of carbocations follows the order: tertiary ($3^ ext{o}$) > secondary ($2^ ext{o}$) > primary ($1^ ext{o}$) > methyl.

Hydride (H) Shift

A carbocation rearrangement where a hydrogen atom shifts a total of one bond to an adjacent carbon.

Alkyl (R) Shift

A carbocation rearrangement where an alkyl group shifts a total of one bond to an adjacent carbon.

Trigonal Planar

A VSEPR shape characterized by 3 electron groups, 0 lone pairs, and a bond angle of $120^ ext{o}$.

Tetrahedral

A VSEPR shape characterized by 4 electron groups, 0 lone pairs, and a bond angle of $109.5^ ext{o}$.

Degree of Unsaturation

Calculated as $\frac{2n+2-m}{2}$, representing the number of rings plus the number of $\pi$ bonds.

$sp^3$ Hybridization

Hybridization state involving 4 total groups (atoms plus lone pairs).

$sp^2$ Hybridization

Hybridization state involving 3 total groups (atoms plus lone pairs).

$sp$ Hybridization

Hybridization state involving 2 total groups (atoms plus lone pairs).

pKa

A measure of acidity; a smaller pKa indicates a stronger acid, while a bigger pKa indicates a stronger base.

Strong Acids

Includes hydroiodic acid ($HI$), hydrobromic acid ($HBr$), hydrochloric acid ($HCl$), sulfuric acids ($H_2SO_4$), sulfonic acids ($RSO_3H$), and nitric acid ($HNO_3$).

Strong Bases

Includes hydroxide ($HO^-$), alkoxides ($RO^-$ like tert-butoxide), amines ($R_2N^-$), and carbanions ($R_3C^-$).

Conformers

Molecules with the same molecular formula and connectivity that differ only by rotation around single bonds.

Constitutional Isomers

Molecules with the same formula but different connectivity.

Enantiomer

Mirror image molecules with the same formula where all chiral centers are inverted.

Diastereomers

Stereoisomers that are not mirror images, sharing the same formula but having some (not all) different stereocenters.

Stereoisomer Formula

The number of stereoisomers can be calculated as $2^n$ where $n$ is the number of chiral centers.

Lindlar Catalyst

A reagent used to control alkyne reactions.

MCPBA

A reagent used in the formation of epoxides from alkenes.

Very Good Leaving Groups

Species such as $RSO_3^-$ (e.g., tosylates, triflates) and $I^-$.

Phenyl Group

A functional group with the formula $C_6H_5$-.

Benzyl Group

A functional group with the formula $-CH_2C_6H_5$.

Anti Conformer

The lowest energy Newman projection configuration where the largest groups are separated by a $180^ ext{o}$ dihedral angle.

Gauche Conformer

A Newman projection configuration with medium energy where large groups have a $60^ ext{o}$ dihedral angle.

$S_N1$ Reaction

A 2-step mechanism involving a carbocation intermediate and a rate law of $ext{rate} = k[ ext{substrate}]$.

$S_N2$ Reaction

A 1-step mechanism featuring a backside attack, inversion of stereochemistry, and a rate law of $ext{rate} = k[ ext{substrate}][ ext{nucleophile}]$.

Zaitsev Product

The more substituted alkene product favored by small bases in elimination reactions.

Hofmann Product

The less substituted alkene product favored by bulky bases or poor leaving groups in elimination reactions.