文档介绍：40-042 Analytische Chemie IV
Structure Determination
by
NMR
Prof. Bernhard Jaun
Office: ETH Hönggerberg HCI E317
Phone: 01 632 31 44
e-mail: .
home page:
Prof. B. Jaun: Structure determination by NMR / Analytische Chemie IV 2
Contents
1. Practical aspects of pulse Fourier transform NMR spectroscopy
The basic NMR experiment: physical description
Excitation by RF pulses
Digitization, window functions and fourier transform
Quadrature detection
Phase cycles and Z-gradients
Dynamic range and solvent suppression
The ponents of an NMR spectrometer
2. The principle of 2D-NMR
The basic idea
A meaningless experiment
Quadrature detection in ω1
3. Homonuclear shift correlation through scalar couplings
COSY.
Determination of coupling constants from COSY cross peaks.
TOCSY
INADEQUATE: homonuclear 13C-13C double quantum spectroscopy.
4. Spectral editing
Spin echo building blocks
Heteronuclear J-modulation
Polarisation transfer: INEPT and DEPT
5. Heteronuclear shift correlation through one bond and long range couplings
Proton detected methods
Proton detected H,X-COSY
HSQC and HMQC
HMBC
Prof. B. Jaun: Structure determination by NMR / Analytische Chemie IV 3
6. Relaxation, dipole-dipole couplings and NOE
Longitudinal and transversal relaxation
NOE in a two spin system without scalar coupling
The mechanism of dipolar relaxation
7. Homonuclear 1D-NOE difference spectroscopy
The steady state NOE in homonuclear multi-spin systems
Practice of 1D-NOE difference spectroscopy
8. ic NOE-spectroscopy
NOESY
NOE in the rotating frame: ROESY
9. On the influence of dynamic processes on NOE spectra
Overall molecular tumbling, internal rotation (conformational changes) und
chemical exchange
How to proceed with molecules with ω0τc near 1
10. Combined application of several