Generalized semiempirical relationship for calculating nuclear spin-spin coupling constants between directly bonded atoms

A new generalized semiempirical relationship for calculating indirect nuclear spin-spin coupling constants between directly bonded atoms has been derived, in this Letter, by using certain approximation. This relationship, which not only involves the contribution of the Fermi contact mechanism, but also involves the contributions of all the non-contact mechanisms, does not depend much on the molecular orbital approximation level, and therefore may be effectively employed at any molecular orbital approximation level. For illustration, the relationship has been employed to successfully elucidate the C-F coupling constants. The calculated results are in good agreement with the corresponding experimental data.