Foundations & Enolate/Carbonyl Chemistry
The deepest, most rigorous ChemVidya build yet. Two layers on every reaction — a slow, hand-held beginner path and a research-grade advanced/reference path — so one book carries a reader from “I have never pushed an arrow” to “I can propose a mechanism a referee would accept.”
The 21 sections in Part 1
- 1Bonding, hybridisation and orbitals Free below
- 2Electronegativity, bond polarity and the dipole map
- 3Acids, bases and pKa reasoning
- 4Nucleophiles & electrophiles — the HOMO–LUMO picture
- 5Curved arrows, taught slowly
- 6The reactive intermediates — structure & stability
- 7Resonance vs induction (and the enolate)
- 8Stereochemistry primer — R/S, E/Z, prochirality
- 9Thermodynamic vs kinetic control
- 10The Aldol reaction (addition & condensation)
- 11Claisen & Dieckmann condensations
- 12The Mannich reaction
- 13Michael addition & the Robinson annulation
- 14Knoevenagel, Perkin & Doebner condensations
- 15Cannizzaro & Tishchenko reactions
- 16Benzoin condensation & Stetter reaction (umpolung)
- 17Darzens glycidic ester condensation
- 18The Reformatsky reaction
- 19The Stork enamine synthesis
- 20The Haloform reaction
- 21Hell–Volhard–Zelinsky (HVZ) α-halogenation
Bonding, hybridisation and orbitals
Free extractSection A.1 of Part 1, reproduced in full from the book — figures and all. No sign-in, no paywall on this section.
A covalent bond is two electrons shared in a molecular orbital built by overlapping two atomic orbitals. Overlap head-on along the internuclear axis gives a σ bond (strong, free rotation); sideways overlap of two p orbitals gives a π bond (weaker, no rotation, and — crucially for us — a cloud of electron density above and below the plane that is easy for a reagent to reach).
Carbon reorganises its 2s and 2p orbitals into equivalent hybrid orbitals so it can form the strongest, least-strained set of bonds. Three cases cover essentially all of organic chemistry:
| Hybridisation | Geometry / angle | Example | What it means for reactivity |
|---|---|---|---|
| sp3 | tetrahedral, 109.5° | CH4, C in an alcohol | four σ bonds; saturated, unreactive unless a leaving group / acidic C–H is present |
| sp2 | trigonal planar, 120° | C=O, C=C, carbocation, aromatic ring | one π bond or empty p orbital; this is where most reactions start |
| sp | linear, 180° | nitrile C≡N, alkyne | two π bonds; high s-character → more electronegative, more acidic C–H |
A rule you will use constantly: more s-character holds electrons closer to the nucleus. An sp orbital (50% s) is more electronegative than sp2 (33%) than sp3 (25%). That single fact explains why a terminal alkyne (sp C–H, pKa ≈ 25) is far more acidic than an alkane (sp3, pKa ≈ 50): the sp carbanion holds the negative charge much better.
Read the rest of Part 1
The remaining 20 sections of this part — Electronegativity, bond polarity and the dipole map, Acids, bases and pKa reasoning, Nucleophiles & electrophiles — the HOMO–LUMO picture, Curved arrows, taught slowly — and all nine parts of Named Reactions are part of ChemVidya Full Access, along with the other books, 55 Study Notes and 6,000+ practice questions.
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