1. NMR: Information Obtained from a Spectrum
An NMR Spectrum will generally provide three types of information:
Chemical Shift – indicates the electronic environment of the nucleus (shielded or deshielded)
Integration – gives the relative number of nuclei producing a given signal. The integral (area under the curve) is drawn on the spectrum by the instrument.
Spin-Spin Coupling – describes the connectivity

2. NMR: Integration Indicates Relative Number of Nuclei
Integral has relative height 9
Relative height 2
The height of the integration line (“integral”) gives you the relative number of nuclei producing each signal.

3. NMR: Information Obtained from a Spectrum
An NMR Spectrum will generally provide three types of information:
Chemical Shift – indicates the electronic environment of the nucleus (shielded or deshielded)
Integration – gives the relative number of nuclei producing a given signal
Spin-Spin Coupling: - describes the carbon connectivity follows the “n+1”rule”

4. NMR: Splitting into a Doublet
Note that the red signal at 1.6 ppm for the methyl group is split into two peaks.
Remember that this is one signal, composed of two separate peaks.

5. NMR: Signal Splitting, n+1 Rule
A signal is often split into multiple peaks due to interactions with protons on carbons next door. Called spin-spin splitting
The splitting is into one more peak than the number of H’s on adjacent carbons (“n+1 rule”)
Splitting of a signal can give doublets (two peaks), triplets (three peaks), quartets (4 peaks), ect.
The relative intensities given by Pascal’s Triangle: doublet 1 : 1 triplet : 2 : 1 quartet : 3 : 3 : 1 pentet: : 4 : 6 : 4 : 1

6. NMR: Signal Splitting, n+1 Rule
n+1 Rule: A signal in the proton NMR spectrum will be split into n+1 peaks, where n is the number of protons on adjacent carbons.
Example: CH3-CH2-Br
For the Methyl Group – There are two protons ‘next door’ (n=2), so the methyl signal will be split into three peaks (2+1), which is called a triplet. Chemical shift will be about 1.5 (alkane region), integration = 3.
For the CH2 Group – Three protons next door will give a signal with 3+1 = 4 peaks, called a quartet. Chemical shift = 3.3 (heteroatom region), integration = 2.

7. NMR: Signal Splitting, n+1 Rule
Peak Heights -
Pascal’s Triangle doublet : 1 triplet : 2 : 1 quartet : 3 : 3 : 1 pentet 1 : 4 : 6 : 4 : 1