90 likes | 183 Vues
NMR Spectroscopy. Chapters 19. Peak Shifts in NMR. e- in molecule is in mag. field e- circulate => produce secondary mag. field opposite in direction to B o *nucleus experiences mag. Field smaller than original B o . -nucleus is shielded
E N D
NMR Spectroscopy Chapters 19
Peak Shifts in NMR • e- in molecule is in mag. field • e- circulate => produce secondary mag. field opposite in direction to Bo *nucleus experiences mag. Field smaller than original Bo. -nucleus is shielded -shielding related to e- density (plus exceptions)
60,000,400 100,000,400
Isotropy – same in all directions Anisotropy – depends on orientation of molecule in magnetic field.