Hydrogen heteronuclear coupling

The coupling between and its attached hydrogens is called heteronuclear coupling... 

Hydrogen fluoride (HF), a molecule that contains only two atoms linked by a covalent bond, exhibits heteronuclear spin/spin coupling. For example, in the absence of coupling between the nuclei, a single signal would be observed in the ]H NMR spectrum of HF because there is only one hydrogen atom. However, when the experiment is conducted, two signals of equal intensity are observed. 

When attempting to unravel the complex structure of an unknown molecule from its l3C and H spectra, it is often quite helpful to determine which hydrogens are connected to which carbons. In the parlance of 2D NMR, we wish to find out which H signals are correlated (associated via one-bond C-H coupling) with which l3C signals. The technique we will use involves heteronuclear (e.g., carbon vs. hydrogen) chemi-... 

The use of heteronuclear /hc and homonuclear 7hh couplings, including /hc.ohj for stmcture elucidation of gangliosides has been reviewed by Acquotti and Sonnino. " The couplings have been used to obtain information on the types of monosaccharides, their conformation, anomeric configuration and hydrogen bonding network. 

Correlations between H and 13C nuclei via scalar couplings can be shown by two-dimensional COSY spectra (4-6). This is exemplified by a heteronuclear (]H,3C) COSY spectrum of 7-methoxycoumarin (B7-4, hemiarin) shown in Fig. 3a (bottom). The cross-peaks connect the signals of hydrogen and carbon atoms directly attached. 

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