Infrared Spectroscopy (OCR A-Level Chemistry A): Flashcards

$\text{cm}^{-1}$ (range: $200-4000 \text{ cm}^{-1}$)

Stretching and bending

Below $1500 \text{ cm}^{-1}$, unique to each molecule

$3200-3600 \text{ cm}^{-1}$ (sharp peak)

$1630-1820 \text{ cm}^{-1}$ (typically $\sim 1700$)

$2500-3300 \text{ cm}^{-1}$ (very broad peak)

C=O ($\sim 1700$) + broad O-H ($2500-3300 \text{ cm}^{-1}$)

Transmittance (%) vs wavenumber ($\text{cm}^{-1}$)

Downward dips on transmittance graph

Both the specific bond AND the functional group