1H NMR Interpretation

1
1H NMR Interpretation

1. Number of Signals (Resonances)
2. Positions of Signals Chemical Shift
3. Relative Intensities of Signals Integrals
4. Splitting Patterns Spin-Spin Coupling
5. Exchangeable Protons

2
Number of Signals Simple Cases
3
Number of Signals and Stereochemistry

• Watch out when you have rings and/or douuble
  bonds! To determine equivalent protons in
  cycloalkanes and alkenes, always draw all bonds
  to hydrogen.

4
Number of Signals in a Cyclic Compound

• Proton equivalency in cycloalkanes can be
  determined similarly.

5
Positions of Signals - Local Diamagnetic Shielding
6
Positions of Signals Induced Anisotropic
Shielding - Benzene

• In a magnetic field, the six ? electrons in a
  benzene ring circulate around the ring creating a
  ring current.
• The magnetic field induced by these moving
  electrons reinforces the applied magnetic field
  in the vicinity of the protons.
• The protons feel a stronger magnetic field and
  thus are deshielded. A higher frequency is needed
  for resonance.

7
Experimental Validation