Heteronuclear Magnetic Double Resonance

摘要: Publisher Summary A number of double resonance techniques that have been applied to homonuclear systems also considerable potential in the heteronuclear field. These include spin saturation studies chemical exchange and use nuclear overhauser effect for direct study molecular geometry. theoretical comparison between various methods decoupling shows even most favorable circumstances, necessary r.f. field is nearly ten times greater, with unmodulated resonance, than either two modulated versions. When interchange a pair nuclei occurs as result internal rotation, rather true exchange, effects can give relative signs coupling constants different conformers. Several manufacturers NMR spectrometers offer facilities perform experiments. The chapter outlines experiments main objective achieve spectral simplification by elimination spin-spin splittings or quadrupole broadening. advantages determination shift X are: (1) convenience; (2) high sensitivity detection observed nucleus; (3) precision; (4) single reference be used. explains magnitudes simple complex systems.