Interaction of Curved and Flat Molecular Surfaces. The Structures of Crystalline Compounds Composed of Fullerene (C60, C60O, C70, and C120O) and Metal Octaethylporphyrin Units

Solutions of C60, C60O, or C70 and metal complexes of octaethylporphyrin (OEPH2) yield crystals that contain both the fullerene and the porphyrin. The structures of C60·2CoII(OEP)·CHCl3, C60·2ZnII(OEP)·CHCl3, and C60O·2CoII(OEP)·CHCl3 are isomorphous and contain an ordered C60 cage surrounded by two MII(OEP) units. Although there is no covalent bond between the fullerene and porphyrin components, the separation between these units is shorter than normal van der Waals contact. Crystals of C70·CoII(OEP)·C6H6·CHCl3, C70·NiII(OEP)·C6H6·CHCl3, and C70·CuII(OEP)·C6H6·CHCl3 are also isomorphous with an ordered fullerene, but have only one porphyrin/fullerene contact. Crystalline C60·ClFeIII(OEP)·CHCl3 lacks the close face-to-face porphyrin/porphyrin contact that is common to all of the other structures reported here but retains the intimate contact between the porphyrin and the fullerene. In (C120O)·CoII(OEP)·0.6C6H6·0.4CHCl3 the fullerene dimer is enclosed by two CoII(OEP) moieties. Unfortunately disorder in the fullerene portion obscures details of the geometry of the bridging region between the fullerenes.