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Dear colleagues! 13C-1H J-couplings are essential in some areas of molecule structure research.

I discovered modern methods implemented in our software and found the following:

  1. 13C J-resolved (recommended by Braun, Berger, Kalinovksy in 150 and more NMR experiments)
  2. J-HMBC (once I used it, but as I remember, it would't work with J<2Hz)
  3. 1H selective TOCSY from 13C satellites that reveals indirect couplings, doesn't help for overlapping signals.

I ask your ideas about fast, selective and robust method for measurements of several couplings in the molecule.

Thank you!

asked Nov 11 '11 at 02:46

VVK's gravatar image

VVK
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5 Answers:
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Thank you very much, I'd like to try SPT also, as direct method.

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answered Nov 29 '11 at 12:37

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VVK
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Did you try HETLOC? It is very accurate in special for small 2,3J C-H constants. Alberto

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answered Nov 26 '11 at 02:29

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ALBERTO PLAZA
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I recommend you try the experiments developped on our group... very easy to measure ;)

  • Optimum spin-state-selection for all multiplicities in the acquisition dimension of the HSQC experiment. Authors: P. Nolis, J. F. Espinosa, and T. Parella Reference: J. Magn. Reson., 180, 39-50 (2006). DOI:10.1016/j.jmr.2006.01.003

  • Improved NMR methods for the direct 13C-satellite selective excitation in overlapped 1H-NMR spectra Authors: P. Nolis, S. Gil, J.F. Espinosa and T. Parella Reference: Magn. Reson. Chem., 47, 121-132 (2009). DOI: 10.1002/mrc.2363

  • IPAP-HSQMBC: Measurement of Long-Range heteronuclear Coupling Constants from Spin-State Selective Multiplets Authors: S. Gil, J.F. Espinosa, and T. Parella Reference: J. Magn. Reson., 207, 312-321 (2010).

  • “Measurement of long-range proton-carbon constants from pure in-phase 1D multiplets”, by Juan F. Espinosa, Paloma Vidal, Teodor Parella and Sergi Gil: Magnetic Resonance in Chemistry 49, 502-507 (2011). DOI:10.1002/mrc.2782

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answered Nov 24 '11 at 03:36

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nolis
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You may try to use a sequence from Bax and Freeman article. JACS, 1982, 104, 1099-1100. It all depends on your particular purposes. Sometimes non-decoupled 13C is enough. And (IMHO) better to use carbon-detected experiments, because indirect detection experiments are wasted by 1H-1H J's and hard to analyze (Look at Furihata, Tashio and Seto article Magn. Reson. Chem., 2011, 49, 53-58)

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answered Nov 22 '11 at 01:45

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Nikolay Boev
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updated Nov 22 '11 at 01:49

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Maybe you can try inadequate experiment.

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answered Nov 13 '11 at 23:38

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jinghere
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