COSY (COrrelation SpectroscopY) and TOCSY (TOtal Correlation Spectroscopy) experiments are very common. Although both experiments provide a diagonally symmetric two dimensional contour plot with the one dimensional spectrum on the diagonal and correlations off of the diagonal, they have different information content. A COSY spectrum will have off-diagonal correlations between coupled spins whereas a TOCSY spectrum will have off-diagonal correlations between all spins in a spin system. For example, consider a spin system where A is coupled to B, B is coupled to C, and C is coupled to D. A COSY spectrum will have correlations between A and B, B and C, and C and D, whereas a TOCSY spectrum will have correlations between all of the spins. This is illustrated in the figure below for 3-heptanone. In this case, there are two spin systems (one on either side of the carbonyl group). The COSY spectrum shows correlations between adjacent spins whereas the TOCSY spectrum shows correlations between all of the spins in each of the two spin systems.
Organic Chemists from Industry and academics to Interact on Spectroscopy Techniques for Organic Compounds ie NMR, MASS, IR, UV Etc. Starters, Learners, advanced, all alike, contains content which is basic or advanced, by Dr Anthony Melvin Crasto, Worlddrugtracker, email me ........... amcrasto@gmail.com, call +91 9323115463 India skype amcrasto64
................DR ANTHONY MELVIN CRASTO Ph.D ( ICT, Mumbai) , INDIA 25Yrs Exp. in the feld of Organic Chemistry,Working for GLENMARK GENERICS at Navi Mumbai, INDIA. Serving chemists around the world. Helping them with websites on Chemistry.Million hits on google, world acclamation from industry, academia, drug authorities for websites, blogs and educational contribution
Pages
- Home
- ABOUT ME
- DIMENSIONS IN NMR SPECTROSCOPY
- 13 C NMR
- 1H NMR
- CHEMDOODLE/INTERACTIVE SPECT PREDICT
- Animations
- HELP ME
- Multinuclear NMR Spectroscopy
- Examples of 13C NMR
- Books on NMR spectroscopy
- UV-Visible Spectroscopy
- IR SPECTRA EXAMPLES
- Journals
- Organic spectroscopy site
- Spectroscopy sites
- IR SPECTROSCOPY
- Books-2
- Recommended Web Sites for Spectra and Spectrum-rel...
- DISCLAIMER
- Mössbauer spectroscopy
- FINDING CHEMICAL SPECTRA
- Mass Spectrometry
- NMR Overview
- Characterisation of Organic Compounds
- SDBS Spectral Database System for Organic Compounds
- CHEMICAL SHIFT
- MASS SPECTROSCOPY
- Books-1
- MASSBANK PORTAL
- 11B NMR
Tuesday, 25 November 2014
COSY VS TOCSY
COSY (COrrelation SpectroscopY) and TOCSY (TOtal Correlation Spectroscopy) experiments are very common. Although both experiments provide a diagonally symmetric two dimensional contour plot with the one dimensional spectrum on the diagonal and correlations off of the diagonal, they have different information content. A COSY spectrum will have off-diagonal correlations between coupled spins whereas a TOCSY spectrum will have off-diagonal correlations between all spins in a spin system. For example, consider a spin system where A is coupled to B, B is coupled to C, and C is coupled to D. A COSY spectrum will have correlations between A and B, B and C, and C and D, whereas a TOCSY spectrum will have correlations between all of the spins. This is illustrated in the figure below for 3-heptanone. In this case, there are two spin systems (one on either side of the carbonyl group). The COSY spectrum shows correlations between adjacent spins whereas the TOCSY spectrum shows correlations between all of the spins in each of the two spin systems.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment