Improving NMR-spectra

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Presentation transcript:

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

Spin decoupling

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.

The effect of higher magnetic field

Shifts reagents

Effect of relaxation reagents

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

Spin-lattice relaxation, T1

Spin-spin relaxation, T2

Τ1 is inverse proportional to # og H’s