1. Improving NMR-spectra
More powerful magnetic field
Shift reagents
Relaxation reagents
Spin dekobling

2. Spin decoupling

5. Summary spin decoupling
Selective 1H irradiation:
Decoupling of all nuclei whic are
coupled to the irradiated nuclei.
Selective 1H irradiation:
Decoupling of only the one C
bonded to the H.
Broad band decoupling: All H’s
irradiated and every non-
equivalent C will give one line.
Powerful irradiation of all H’s:
Keeps the coupling information,
multiplets with small constants.

6. The effect of higher magnetic field

7. Shifts reagents

8. Effect of relaxation reagents

9. Two types of relaxation
Z-direction: τ1 Spin-lattice relaxation
xy-plane: τ2 Spin-spin relaxation

10. Spin-lattice relaxation, T1

11. Spin-spin relaxation, T2

12. Τ1 is inverse proportional to # og H’s