Nuclear Magnetic Resonance NMR

1
Nuclear Magnetic Resonance (NMR)

• Some atomic nuclei, but not all, have a property
  called spin which results in multiple energy
  states when placed in a magnetic field.
• Atoms which are in equivalent environments in a
  molecule behave equivalently.
• Anything near an electronegative element will
  appear at a larger chemical shift.
• Peak areas approximate the number of atoms in a
  particular environment.
• Hydrogens on adjacent carbons can affect each
  others environment splitting according to n1
  rule.

2
Information From 1H-NMR Spectrum

• Number of regions of peaks equals number of
  unique hydrogen environments
• Coupling can be used to determine which sets of
  hydrogens are adjacent to other sets.
• Integrations can tell about the relative number
  of hydrogens in each environment.
• Location of peaks can indicate adjacency to
  electronegative atoms.

3
Information From 13C-NMR Spectra

• Only single peaks observed (no coupling).
• No integrations possible.
• Carbon spectra interpreted strictly on the number
  of peaks and their respective locations.