On the qualitative theoretical NMR chemical shifts of model carbyne catenanes and knots

The qualitative 13C NMR chemical shift (δ) calculated for carbyne: cycles (C10,C20,…,C60), catenanes (C10C30 and C20C30), knots (C30 and C60 trefoil, and C40 and C64 figure-8), have shown δ to tend to alternate along the catenane or a knot branch and to follow neither the change in the partial charge nor the change in the angles. The δ alternation is associated with the repulsion between catenane components or knot branches which polarizes the π electrons so that the atoms of each CC bond are differentiated to one closer to and one other further from the perturbation.