Fig. 8. Structures and energetics for the rotation of one phenylene panel. A dihedral angle at the phenylene–phenylene linkages shown with ball-and-stick models was constrained and rotated by 5°. At each constrained point, the most stable structure was obtained by low-mode conformational search calculations (1000 steps) with the MM3* force field (MacroModel), and the energy was obtained by single-point DFT calculations with B3LYP/6-31G(d,p) (Gaussian). The global minima at 35° are shown in blue, and the high energy conformers at 0° are shown in red. The structures were overlaid by minimizing the root-mean-square deviation of the atomic positions (RMSD) of one reference phenylene panel. (a) 5Me-[5]CMP. RMSD for all of the atoms was 1.633 Å. (b) 6Me-[6]CMP. RMSD for all of the atoms was 0.859 Å.