Functional group recognition sheet
Hydrocarbons
| Group | General formula | Polarity | IR bands | ¹H NMR | ¹³C NMR |
|---|---|---|---|---|---|
| Alkane | CₙH₂ₙ₊₂ | nonpolar | 2850-3000 cm⁻¹ (C-H stretch) | 0.9-1.5 ppm | 10-40 ppm |
| Alkene | CₙH₂ₙ | nonpolar | 1620-1680 cm⁻¹ (C=C stretch), 3000-3100 cm⁻¹ (=C-H stretch) | 4.5-6.5 ppm (vinyl H) | 100-150 ppm |
| Alkyne | CₙH₂ₙ₋₂ | slightly polar | 2100-2260 cm⁻¹ (C≡C stretch), 3300 cm⁻¹ (≡C-H stretch, terminal) | 1.8-3.0 ppm (terminal ≡C-H) | 65-90 ppm |
Oxygen
| Group | General formula | Polarity | IR bands | ¹H NMR | ¹³C NMR |
|---|---|---|---|---|---|
| Alcohol | R-OH | polar | 3200-3600 cm⁻¹ (O-H stretch, broad), 1050-1150 cm⁻¹ (C-O stretch) | 1-5 ppm (O-H, variable), 3.4-4.0 ppm (C-H next to O) | 50-90 ppm |
| Aldehyde | R-CHO | polar | 1720-1740 cm⁻¹ (C=O stretch), 2700-2850 cm⁻¹ (aldehyde C-H stretch, two peaks) | 9.5-10.0 ppm (CHO) | 190-205 ppm |
| Ketone | R-CO-R' | polar | 1705-1725 cm⁻¹ (C=O stretch) | 2.1-2.6 ppm (α-H) | 195-220 ppm |
| Carboxylic Acid | R-COOH | very polar | 2500-3300 cm⁻¹ (O-H stretch, very broad), 1700-1725 cm⁻¹ (C=O stretch) | 10-12 ppm (COOH) | 170-185 ppm |
| Ester | R-COO-R' | polar | 1735-1750 cm⁻¹ (C=O stretch), 1000-1300 cm⁻¹ (C-O stretch) | 3.7-4.1 ppm (OCH₃), 2.0-2.5 ppm (α-H) | 160-175 ppm (C=O), 50-70 ppm (O-C) |
Built from the functionalGroups collection. Polarity and the three spectroscopic signatures come from each record's own properties and spectroscopy fields.