What is the difference between COSY and HSQC?
All Answers (7) 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 does a COSY NMR tell you?
COSY tells you “what proton is coupled to what proton.” Protons that are two, three, or sometimes four bonds apart may show cross peaks. The magnitude of the couplings affects the peak intensity.
Is HSQC phase sensitive?
The HSQC spectrum that you have just run is phase sensitive. You must phase it. An out-of-phase spectrum will look strange and will show dramatic intensity differences on either side of all peaks. To phase a 2D spectrum, one extracts individual 1D rows or columns and phases the 1D spectra.
What is HSQC used for?
The HSQC (Heteronuclear Single Quantum Coherence) experiment is used to determine proton-carbon single bond correlations, where the protons lie along the observed F2 (X) axis and the carbons are along the F1 (Y) axis.
What is HSQC and Hmbc?
HSQC is an NMR experiment that gives communication between a 1H resonance with a carbon resonance for H and C that are attached respectively. So this is H-C single bond correlation whereas HMBC is correlation for 1H resonance and 13C resonance that are either 2, 3 or 4 bonds away.
What does HSQC stand for NMR?
heteronuclear single quantum coherence
The heteronuclear single quantum coherence or heteronuclear single quantum correlation experiment, normally abbreviated as HSQC, is used frequently in NMR spectroscopy of organic molecules and is of particular significance in the field of protein NMR.
How does HSQC work?
HSQC works by transferring magnetization from the I nucleus (usually the proton) to the S nucleus (usually the heteroatom) using the INEPT pulse sequence; this first step is done because the proton has a greater equilibrium magnetization and thus this step creates a stronger signal.
What is HSQC NMR?
What are COSY and Noesy Spectra?
Nuclear Overhauser effect spectroscopy (NOESY) The spectrum obtained is similar to COSY, with diagonal peaks and cross peaks, however the cross peaks connect resonances from nuclei that are spatially close rather than those that are through-bond coupled to each other.
How do you read COSY NMR?
¹H-¹H Correlation Spectroscopy (COSY) shows the correlation between hydrogens which are coupled to each other in the ¹H NMR spectrum. The ¹H spectrum is plotted on both 2D axes….Step 2: ¹H-¹H COSY.
| Chemical Shift (ppm) | COSY correlations | Assignment |
|---|---|---|
| 1.770 | 3-4 | 3 |
How do you interpret a COSY spectrum?
How do you read HSQC Tocsy?
To interpret the HSQC-TOCSY spectrum, one should start with the direct correlation HSQC peaks. For example, in the HSQC the 1 (anomeric) proton and carbon are at 5.42 ppm and 92 ppm, respectively. TOCSY then transfers proton signal to coupled protons such as the 2, 3, 4, and 5 protons.