Clamshell Arrangements and Chirality in Cocrystals of C₇₀ with M^II(octaethylporphyrin) (M = Co or Zn)

Abstract

Two new cocrystals, 2C70·3CoII(OEP)·2CHCl3 (1) (OEP is the dianion of octaethylporphyrin) and C70·2ZnII(OEP)·o-xylene (2), with a clamshell arrangement of two porphyrins about a central C70 were grown and structurally characterized. The cocrystal 2C70·3CoII(OEP)·2CHCl3 (1) possess a unique double-clamshell arrangement in which there are two distinct compartments for the fullerenes and a distorted CoII(OEP) molecule that is sandwiched between two C70 molecules. C70·2ZnII(OEP)·o-xylene (2) has a simple clamshell arrangement of two ZnII(OEP) molecules surrounding the C70 molecule, with the clamshells arranged into chains through close face-to-face contacts between the porphyrins. In contrast, C70·ZnII(OEP)·1.5p-xylene (3) has a more common structure with the C70 molecule in close proximity to only one ZnII(OEP) molecule.