Heteronuclear Relayed Proton Correlated Spectroscopy HERPECS

1 Heteronuclear Relayed Proton Correlated Spectroscopy (HERPECS) 

In the relayed coherence transfer experiment the first step is an initial homonuclear magnetization transfer (i.e., from proton A to proton B). The coherence is then relayed to a third nucleus, which may be a proton (homonuclear relay) or a different nucleus (e.g., heteronuclear relay). Recently, another variation of the relay experiment has been reported which involves transfer of coherence to a heteronuclear spin as the first step ( H-X heteronuclear shift correlation). The coherence is then relayed to a third nucleus, a proton (X- H coherence transfer), which is the nucleus observed.  

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Figure 5.79. (A) In heteronuclear relayed proton correlated spectroscopy (HERPECS), the coherence is transferred first from to a heteronuclear spin, X, and is then relayed and detected at the third nucleus, Hg. (B) A schematic representation of INADEQUATE, H,H-COSY, and H,C-COSY, relayed H,C-COSY, H,C-COLOC, and HERPECS experiments.

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