Chapter 1: Hybridization and Carbon Bonding

Carbon's unique ability to form four covalent bonds arises from its electronic configuration (2, 4). Hybridization is the mathematical mixing of atomic orbitals to form new orbitals of equal energy:

As s-character increases: bond length decreases, bond strength increases, electronegativity increases, and acidity of attached H increases.

Chapter 2: IUPAC Nomenclature

The naming system assigns one unambiguous name to each compound. Steps: (1) longest chain with principal group, (2) lowest locant to principal group, (3) alphabetical prefixes for substituents, (4) suffix from the functional group hierarchy (carboxylic acid > aldehyde > ketone > alcohol > amine).

Key functional group suffixes: -oic acid (COOH), -al (CHO), -one (C=O), -ol (OH), -amine ($NH_{2}$). SMILES examples: ethanoic acid CC(=O)O, propanal CCC=O, propan-2-one (acetone) CC(=O)C, ethanol CCO, ethylamine CCN.

Chapter 3: Isomerism

Structural isomerism — same molecular formula, different connectivity. Four subtypes: chain, position, functional group, metamerism.

Stereoisomerism — same molecular formula and connectivity, different spatial arrangement.

• Geometrical (E/Z): needs restricted rotation + different groups on each end of the double bond.
• Optical: needs a chiral center (asymmetric carbon — four different groups).

Chapter 4: Electronic Effects

Three effects govern organic reactivity:

Inductive Effect (I): Through σ bonds; +I (alkyl) donates, -I (electronegative groups) withdraws. Decreases with chain length.

Mesomeric Effect (M): Through π conjugation; +M (-OH, -$NH_{2}$) donates lone pair, -M (-$NO_{2}$, -CHO) withdraws.

Hyperconjugation: σ electrons of alpha C-H bonds delocalize into adjacent empty p-orbital or π system. Each alpha C-H bond contributes one hyperconjugative structure. Stabilizes carbocations, radicals, and alkenes.

Chapter 5: Reaction Intermediates and Bond Fission

Homolytic fission → free radicals (each fragment gets one electron). Favored by heat/light, nonpolar conditions.

Heterolytic fission → ions (carbocations or carbanions). Favored by polar solvents and polar bonds.

Stability summary:

• Carbocation: 3° > 2° > 1° > $CH_{3}^{+}$ (more alkyl groups = more stabilization)
• Carbanion: $CH_{3}^{-}$ > 1° > 2° > 3° (more alkyl groups = less stable — they push electrons onto the negative center)
• Free radical: 3° > 2° > 1° > $CH_{3}$· (mirrors carbocation)

Chapter 6: Reaction Classification