Larry G. Faehl

Alternate π-Bond Routes for Carbon-13-Carbon-13 Spin-Spin Coupling - Hyperconjugative σ-π vs Non-Classical p-p Interactions

Abstract In a previous report1 longer-range carbon-13-carbon-13 spin-spin coupling up to five bonds was noted in 13C-carboxyl-9,10-dihydro-9-anthroic acid. Although many types of longer-range proton-proton couplings in various π-systems are known2 (e.g., cumulenes) which may portend analogous π-systems in carbon-carbon couplings, this type of carbon-carbon coupling observed in 9,10-dihydro-9-anthroic acid has no analogy in proton-proton coupling, since proton cannot be incorporated within a ring.