Coupling constant variation with dihedral angle

FIGURE 5.2 Calculated variation of vicinal and allylic proton-proton coupling constants with dihedral angle between the C—H bonds shown. 

Figure 4.21. A diagrammatic representation of the Karpins relationship showing the variation of coupling constant with dihedral angle snbtended between neighboring protons that are coupled to each other.

Martin Karpins was the first to study the variation of the coupling constant Vhh with the dihedral angle or and developed an equation (Eq. 7.3) that gave a good fit to the experimental data shown in the graph in Figure 7.7. The Karpins relationship takes the form... 

Figure 2.50. Variation of coupling constants with dihedral angle for non-...

FIGURE 5.7 The Karplus relationship—the approximate variation of the coupling constant V with the dihedral angle a. 

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