What is the difference between COSY and HSQC?

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 is the difference between Hetcor and HSQC?

HSQC uses 1H for detection and thus will be the most sensitive, while HETCOR uses 13C for detection, which benefits from improved spectral dispersion (i.e. a larger chemical shift range) and avoids detection of the huge in-vivo water signal which can be problematic in HSQC.

Is HSQC a 2D?

HSQC is a 2D experiment that correlates two different atomic nuclei (thus, it is considered a “heteronuclear” experiment).

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.

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.

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.

What is Hetcor?

HETCOR is a type of COSY in which the two frequency axes denotes the chemical shifts for different nuclei, usually 1H and 13C [168]. With a HETCOR experiment, it is possible to relate a peak of a heteroatom to the protons attached to it.

What is 1H 15N HSQC?

1H-15N-HSQC spectrum – the “protein fingerprint” • less peaks / better resolution • one peak per amide-group ➢ roughly one peak per residue (fingerprint!!) N.

What are Hmbc techniques?

The 3D HMBC technique is a widely used method for the characterization of 1H–13C correlations through small nJ(C,H) couplings between nuclei distant by more than one bond.

What are the two dimensions in an HSQC spectrum?

Heteronuclear single-quantum correlation spectroscopy (HSQC) Each peak in the spectrum represents a bonded N–H pair, with its two coordinates corresponding to the chemical shifts of each of the H and N atoms. Some of the peaks are labeled with the amino acid residue that gives that signal.

What is Hmbc NMR?

The HMBC (Heteronuclear Multiple Bond Correlation) experiment gives correlations between carbons and protons that are separated by two, three, and, sometimes in conjugated systems, four bonds. Direct one-bond correlations are suppressed. This gives connectivity information much like a proton-proton COSY.