Organic Chemistry

Specific groupings of atoms within molecules that have predictable chemical behavior regardless of the rest of the molecule. They are the key to classifying organic compounds and predicting their reactivity, solubility, and physical properties.

Detailed, step-by-step descriptions of how bonds break and form during a chemical reaction, including the movement of electron pairs shown with curved arrows. Understanding mechanisms allows chemists to predict products, stereochemistry, and side reactions.

The study of the three-dimensional arrangement of atoms in molecules and how spatial orientation affects chemical and physical properties. Molecules with the same connectivity but different spatial arrangements (stereoisomers) can have dramatically different biological activities.

A class of reactions in which a nucleophile (electron-rich species) replaces a leaving group on an electrophilic carbon. The two main pathways, SN1 and SN2, differ in kinetics, stereochemical outcomes, and substrate preferences.

A reaction in which an electrophile adds to a carbon-carbon double or triple bond, breaking the pi bond and forming two new sigma bonds. This is the most characteristic reaction type for alkenes and alkynes.

A property of cyclic, planar, fully conjugated molecules that possess a special stability arising from the delocalization of pi electrons according to Huckel's rule ($4n+2$ pi electrons). Aromatic compounds resist addition reactions and instead undergo electrophilic aromatic substitution.

The chemistry of compounds containing the C=O (carbonyl) group, including aldehydes, ketones, carboxylic acids, esters, and amides. The polarized carbonyl bond makes the carbon electrophilic and the oxygen nucleophilic, driving a rich variety of addition and substitution reactions.

Large molecules composed of repeating structural units (monomers) connected by covalent bonds through polymerization reactions. Organic polymers range from synthetic plastics like polyethylene and nylon to biological macromolecules such as proteins, nucleic acids, and polysaccharides.

The use of instrumental techniques such as infrared spectroscopy (IR), nuclear magnetic resonance (NMR), and mass spectrometry (MS) to determine the structure of organic molecules. Each method provides complementary information about functional groups, connectivity, and molecular formula.

A problem-solving strategy for planning organic syntheses by working backward from the target molecule to simpler, commercially available starting materials. Developed by E. J. Corey, it involves identifying strategic bond disconnections and the corresponding forward reactions.