Fig. 5. Depictions of [6]CPP²⁻ (silvery), [8]CPP²⁻ (yellow), [10]CPP²⁻ (golden), and [12]CPP²⁻ (orange), along with a chart of volume comparison between the encapsulated moieties and void space in the solid-state structures. The estimated internal space is shown as a blue-green sphere.