The position of the calixarene alon

The position of the calixarene along the axle was established by looking at the variation in the chemical shifts of the protons of the dumbbell portion between C1 and C1’ relative to those of 6 (see Scheme 2 for numbering). In particular, the protons from C2 to C6’ in 8 undergo a substantial upfield shift, while those from C5’ to a’ are downfield shifted to a much smaller extent. The relative orientation of the dumbbell C6 spacers with respect to the calixarene rims were established through ROESY experiments, which showed cross peaks between protons 4 and 5 of the axle and protons m, n, and o of thewheel (see Supporting Information).