Key Structures in GOC
Hybridization Examples:
| Molecule | SMILES | Hybridization | Bond Angle | Geometry |
|---|---|---|---|---|
| Methane | C | sp3 | 109.5° | Tetrahedral |
| Ethylene | C=C | sp2 | 120° | Trigonal planar |
| Acetylene | C#C | sp | 180° | Linear |
| Carbon dioxide | O=C=O | sp | 180° | Linear |
| Formaldehyde | C=O | sp2 | ~120° | Trigonal planar |
| Propanone | CC(=O)C | sp2 (C=O) | ~120° | — |
Carbocation Structures:
Methyl cation (CH3+): sp2, trigonal planar, empty p-orbital perpendicular to plane.
tert-Butyl cation SMILES: C[C+](C)C — three methyl groups stabilize empty p-orbital.
Resonance Structures:
Acetate ion: CH3COO- has two equivalent resonance structures with C-O bond order = 1.5.
Allyl cation: [CH2+]C=C ↔ C=C[CH2+] — two resonance structures, positive charge shared between C-1 and C-3.
Nitro group: [N+](=O)[O-] in both resonance forms.
Geometrical Isomers:
(E)-but-2-ene: C/C=$\frac{C}{C}$ — methyl groups on opposite sides.
(Z)-but-2-ene: C/C=C\C — methyl groups on same side.