Metallotectons: Comparison of Molecular Networks Built from Racemic and Enantiomerically Pure Tris(dipyrrinato)cobalt(III) Complexes

The structures of a series of crystalline chiral tris(dipyrrinato)cobalt(III) complexes were determined. The peripheries of the selected complexes bear three trigonally directed substituents known to engage in various intermolecular interactions, including COOH, CN, diaminotriazinyl (DAT), and Br. To allow comparison, structures were determined for both racemic and enantiomerically pure complexes in all cases, except that of the Br-substituted compound. The ability of COOH and DAT groups to participate in well-established patterns of intermolecular hydrogen bonding led to structures with predictable features. In particular, crystallization of the racemic DAT-substituted complex yielded a structure built from open hydrogen-bonded sheets, and a significant fraction of the volume of the crystals (40%) proved to be available for the inclusion of guests. Weaker C−H···N and C−H···Br interactions were observed in the structures of the CN- and Br-substituted complexes, which yielded networks that were found to be more closely packed.