Molecular vibrations and functional group frequencies
Infrared (IR) Spectroscopy · Chemistry
Molecule viewer
Interactive 3DBall-and-stick models with true bond angles — switch molecule to compare shapes.
Controls
Drag the sliders or type a value — the simulation updates live.
Study notes
An IR shows strong 1715 cm⁻¹ but no 3600 cm⁻¹. What group? Step 1: 1715 cm⁻¹ = C=O stretching (carbonyl region). Step 2: No 3600 (O–H) → not carboxylic acid or alcohol. Step 3: Carbonyl without O–H → ketone, aldehyde, or ester. Step 4: Check C–H ~2720 (aldehyde) or C–O ~1200 (ester) to narrow. IR eliminates!