We grew crystals of three pseudopolymorphs of c-P6•T6: trigonal P6-II and P6-III, and triclinic P6-IV, followed by a monoclinic C60 cocrystal of the free-base ring P6-C60. All crystals were grown by diffusion of methanol into solutions in odichlorobenzene. P6-III and P6-IV crystallize together, whereas crystallization of P6-II was induced by addition of a small amount of 1,4-diazabicyclo[2.2.2]octane (DABCO) to the solution. DABCO was not found in the crystal structure, (as confirmed by 1 H NMR analysis of dissolved crystals; see Fig. and S37), but its presence facilitates crystallization of this form. The unit cell parameters for all the crystals are summarized in Table .