Carbon-Carbon Correlations
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In the majority of cases a joint analysis of 1H,1H COSY and 1H,13C HMBC spectra is sufficient for structure elucidations of organic compounds. In some cases, however, 13C,13C correlations may be needed in order to determine the structure unambiguously. The availability of the 13C-optimised cryoprobe allows to carry out experiments relying on J(C,C)-couplings within reasonable time frame. As an example, the 2D INADEQUATE spectrum (INAD2D under IconNMR) of the concentrated solution of menthol was acquired in 54 minutes:
Click here for the high-resolution version.
2D INADEQUATE experiment can also be used to detect connectivities of other nuclei. For example, 31P-31P correlations can be verified using the 400 MHz instrument.
A one-dimensional version of INADEQUATE is also available, which allows accurate measurements of J(C,C) couplings.