Organic Chemistry

Structural Diagrams

Different representations of organic molecules that convey chemical and physical properties.

Hybridisation

The process by which atomic orbitals combine to form new hybrid orbitals in organic molecules.

Acidity

The ability of a molecule to donate a proton (H+); more stable anions increase acidity.

Lewis Acid

A molecular entity that acts as an electron-pair acceptor.

Resonance

The delocalisation of electrons within a π-system, leading to increased stability of molecular structures.

pKa

The negative logarithm of the acid dissociation constant (Ka); a more convenient measure of acidity.

Hückel's Rule

A rule stating that cyclic, conjugated molecules exhibit aromaticity if they have (4n + 2) π-electrons.

Chirality

A property of molecules that have non-superimposable mirror images, leading to enantiomers.

Enantiomers

Non-superimposable mirror images of chiral molecules.

Diastereoisomers

Stereoisomers that are not mirror images of each other.

Stereogenic Centre

An atom with four different substituents, responsible for the chirality of a molecule.

Conformational Isomers

Different spatial arrangements of molecules that result from rotation about single bonds.

Optical Activity

The ability of chiral substances to rotate the plane of polarized light.

Acidity and Basicity in Organic Chemistry

Key concepts involving the donation and acceptance of protons by molecular species.

Cyclic Conjugated Structure

A structure where alternating double bonds allow for delocalisation of electrons, crucial for aromaticity.

Amide Bond

A bond formed between an amine and a carboxylic acid; characterized by resonance stabilization.

Peptide Bond

A specific type of amide bond linking amino acids in proteins.

Stereoisomers

Compounds with the same molecular formula and connectivity but different spatial arrangements.

1:1 Racemic Mixture

A sample containing equal amounts of both enantiomers of a chiral molecule.

Geometric Isomers

Isomers that differ in arrangement across a double bond, categorized as cis or trans.