che 440/540 2d-nmr
Post on 30-Dec-2015
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Relaxation delay
90o pulse
t1 (microseconds)
90o pulse
Prototype Pulse Sequence for a 2D-NMR Experiment
Acquire (t2 seconds)
Stacked plot of 22spectra of acetone
Projection of (a)
Resulting interferogram
Origin of the Second Dimension
Basics of HETCOR and HMQC
• Heteronuclear correlated (HETCOR) and heteronuclear multiple quantum coherence (HMQC) spectroscopy show direct correlations between hydrogens and their directly bonded carbons.
• In HETCOR the signal is detected by observing 13C, and in HMQC by observing 1H. The HMQC experiment is shorter, but the pulse sequence is more complicated.
Both give the same information: one-bond 1H-13C correlations
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