What is COSY and HSQC?

Dear Hicham, COSY is a 2D spectrum that shows scalar coupling between vicinal H atoms (via 3 bonds). HSQC on the other hand shows correlation between C and H that is bonded to it (via 1 bond). On one axis you have 13C or DEPT, on the other 1H spectrum.

What does a COSY NMR tell you?

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. This confirms assignments 3 and 4 made from the proton spectrum alone.

What is COSY technique?

COSY is a technique for determining correlations through the chemical bond. In it’s most used form this allows us to see which proton resonances are mutually coupled. Peak of interest, known as ‘cross-peaks’, appear away from the diagonal axis where the two protons are coupled.

What is Hmbc technique?

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. This gives connectivity information much like a proton-proton COSY.

What is COSY used for?

H-1H COSY (COrrelated SpectroscopY) is a useful method for determining which signals arise from neighboring protons (usually up to four bonds). Correlations appear when there is spin-spin coupling between protons, but where there is no coupling, no correlation is expected to appear.

What is HMBC and HSQC?

HMBC combined with COSY, multiplicity edited HMQC or HSQC, and 1D proton and carbon sequences comprise the majority of the standard set of experiments used as a first pass for structural elucidations of impurities and degradants. HMBC provides correlations between carbons that are mainly separated by two or three bonds.

Is HSQMBC-cosy a complementary NMR method to standard HMBC/hszmbc?

HSQMBC-COSY and HSQMBC-TOCSY pulse schemes are evaluated as complementary NMR methods to standard HMBC/HSQMBC … The detection of long-range heteronuclear correlations presenting J(CH) coupling values smaller than 1-2Hz is a challenge in the structural analysis of small molecules and natural products.

What is HMBC spectroscopy?

¹H-¹³C Heteronuclear Multiple Bond Correlation Spectroscopy (HMBC) shows the correlations between protons and carbons that are separated by multiple bonds. The ¹H spectrum is shown on the horizontal axis and the ¹³C spectrum is shown on the vertical axis.

What is HSQC used for in NMR?

– the HSQC experiment is one of the fundamental building blocks of scores of multidimensional, heteronuclear and triple resonance NMR experiments HSQC Spectra of Other Nuclear Pairs •  HSQC (and HMQC, see later) are used to correlate many types of nuclei – for biomolecular NMR, mostly 1H-15N, 1H-13C, 1H-31P, etc. – example below: 13C-103Rh