Metalloporphyrin-Based Inclusion Materials: Exploiting Ligating Topologies and Hydrogen-Bonding Backbones in Generating New Supramolecular Architectures

By coordination of the metal center of tetraphenylmetalloporphyrins (TPMP) [metal center = Zn(II) or Mn(II)] with
pyridyl-based bidentate ligands, namely, N,N‘-bis(4-pyridyl)urea (4BPU), N,N‘-bis(3-pyridyl)urea (3BPU), and N-(4-pyridyl)isonicotinamide (4PIN), various axially modified tetraarylmetalloporphyrins (AMTAMPs) have been crystallographically characterized in their corresponding lattice inclusion complexes. Nine such inclusion crystals are prepared
by crystallizing TPMP and the corresponding bidentate ligands in 1:2 molar ratio from suitable solvent systems.
While the metal center Zn(II) of TPMP leads to the formation of both dimeric and monomeric AMTAMPs due to its
preference for pentacoordinated geometry, the Mn(II) metal center of TPMP forms both polymeric and discrete
hexacoordinated AMTAMPs due to its preference for hexacoordinated geometry. However, there seem to be no
control on the formation of a particular AMTAMP. Structural analyses suggest that most of the AMTAMPs display
new types of packing in the corresponding inclusion crystals.