What is COSY and Hsqc?

Dear Hicham, COSY is a 2D spectrum that shows scalar coupling between vicinal H atoms (via 3 bonds). On both axis you have 1H spectrum and you can see the exact correlations and it can help you resolve structure. HSQC on the other hand shows correlation between C and H that is bonded to it (via 1 bond).

What is COSY experiment?

COSY (Correlated Spectroscopy) was one of the first multidimensional experiments. Cross peaks in COSY are between protons that are coupled. COSY tells you “what proton is coupled to what proton.” Protons that are two, three, or sometimes four bonds apart may show cross peaks.

Which type of peaks are obtained in COSY spectrum?

1. The COSY spectrum as shown in fig. 2 for ethylbenzene (fig. 3) contains a diagonal and cross peaks (signals that are not on the diagonal and correspond to other signals on the same horizontal and vertical projections).

What is COSY NMR used for?

The first and most popular two-dimension NMR experiment is the homonuclear correlation spectroscopy (COSY) sequence, which is used to identify spins which are coupled to each other.

What information is available from the Tocsy experiment?

The total correlation spectroscopy (TOCSY) experiment allows the generation of cross peaks between virtually all spins in the same spin system. A spin system is a group of spins that couples to one or more other members of the group. A molecule may contain one spin system, or it may contain a hundred spin systems.

What is a COSY experiment?

What is gradient COSY?

This Handout covers VnmrJ3. 2A. COrrelation SpectroscopY (COSY) is a 2D NMR technique that gives correlations between J-coupled signals by incrementing the delay between two 90º-proton pulses (see pulse sequence below).

What is Hetcor NMR spectroscopy?

Heteronuclear correlation (HETCOR) spectroscopy is a standard two-dimensional NMR technique. The resolution of 31P{1H} CPMAS spectra is generally not sufficient to unequivocally detect the HPO42− ions and the apatitic OH− ions in bone or dentin samples.

Is Hetcor and HSQC the same?

This experiment is similar to the HSQC (Heteronuclear Single Quantum Correlation) experiment; however, HETCOR is a less sensitive experiment since it is a carbon detected experiment, unlike HSQC which is a proton detected experiment.

What is Noesy NMR used for?

Nuclear Overhauser Effect Spectroscopy (NOESY) is a 2D NMR spectroscopic method used to identify nuclear spins undergoing cross-relaxation and to measure their cross-relaxation rates.

What is the DQF-COSY NMR sequence?

Timothy D.W. Claridge, in High-Resolution NMR Techniques in Organic Chemistry (Third Edition), 2016 The DQF-COSY sequence ( Fig. 6.12) differs from the basic COSY experiment by the addition of a third pulse and the use of a modified phase cycle or gradient sequence to provide the desired selection.

How to calculate 2D NMR cosy and DQF-COSY spectra of an ax system?

Article/chapter can not be redistributed. The 2D NMR COSY and DQF-COSY spectra of an AX system of spins I = 3/2 have been calculated by numerical density matrix calculations. The results are presented in two extreme cases, namely in the slow relaxation regime and in the fast relaxation regime.

What is the difference between the DQF-COSY and cosy experiments?

The DQF-COSY sequence ( Fig. 6.12) differs from the basic COSY experiment by the addition of a third pulse and the use of a modified phase cycle or gradient sequence to provide the desired selection.

How does DQF-COSY work?

The DQF-COSY experiment and coherence transfer pathway. The pulses are phase-cycled as described in the text to select the pathway shown with quad-detection observing the p = –1 magnetisation. The period δ allows for rf phase changes and is typically of only a few microseconds.