Deuterium‐induced NMR isotope shifts for 13C resonance frequencies of norbornane. Quantitative data for the dihedral angle dependence of vicinal shifts

The complete set of deuterium‐induced intrinsic 13C NMR isotope shifts, nΔ(13C), for norbornane have been determined from the isotopomeric monodeuteriated systems, and the results are discussed with respect to structure. No correlation is found between 1Δ values and the s character of the CD bond hybrid. For vicinal isotope effects, however, a quantitative correlation with the dihedral angles of the intervening 13C‐CCD bond fragment can be formulated: | 3Δ(13C) | (ppb) = 2.2 + [7.3 × 10−3(ϕ −117.8)2] Negative 3Δ values are found for bonding pathways in the five‐membered ring partial structure with an anti arrangement of the CCCD bond fragment.