Assign the ¹H NMR Spectrum
Every signal in a ¹H NMR spectrum belongs to a specific set of protons in the molecule. The spectra on this page are reconstructed from published experimental assignments: each line sits at a measured chemical shift from a real compound, redrawn with first-order splitting. Click a signal in the spectrum, then click the proton(s) on the structure that produce it. Note that equivalent protons produce a single signal, so one signal may belong to several positions at once.
¹H Spectrum Reconstructed from Experimental Data
Expansion
Common Questions
How do I match signals to protons?
Use all three pieces of information together: the chemical shift tells you the electronic environment (protons near electronegative atoms or π systems appear downfield), the integration tells you how many protons contribute, and the splitting tells you how many neighbors they have. Assign the easiest signals first and the remaining ones often fall into place by elimination.
Are these spectra real or simulated?
Reconstructed from real measurements — which is different from simulated. Every line position comes from a published experimental assignment of a real compound in nmrshiftdb2; we redraw the spectrum from those measured shifts with first-order splitting and typical coupling constants. What you see is where the signals of the actual molecule sit, drawn cleanly.
What does the zoom view show?
Selecting a signal opens an expansion of that region. At full scale a spectrum spanning 0–14 ppm cannot show coupling constants of a few Hz, so the expansion is where you can actually see the splitting pattern.
Reconstructed from published data: assigned shifts from nmrshiftdb2 (CC BY-SA 4.0) · first-order rendering with typical J values.