Dependence of one-bond deuterium isotope shifts in 13C NMR on CH bond lengths for substituted and unsubstituted aromatic compounds

One-bond deuterium-induced isotope shifts of 13C NMR (1Δ) for 106 sp2-hybridized carbons are discussed in terms of CH bond lengths. 1Δ correlates linearly with the related CH bond length calculated by the MNDO MO method by the equation 1Δ(ppb)=8350 rCH (A) – 8824.