HYDROGEN-BONDED PORPHYRINIC SOLIDS - SUPRAMOLECULAR NETWORKS OF OCTAHYDROXY PORPHYRINS

Symmetrically substituted octohydroxy porphyrins, tetrakis(3',5'-dihyd roxyphenyl)porphyrin H2T(3',5'-DHP)P, tetrakis(2',6'-dihydroxyphenyl)p orphyrin H2T(2',6'-DHP)P, and their Zn(II) and Mn(III) derivatives hav e been developed as building blocks for supramolecular hydrogen-bonded networks. The crystal structures of a series of these porphyrins exhi bit unique structural features through assembly of porphyrin networks by means of directional hydrogen bonding. The position of the peripher al hydroxyl groups, the choice of metallo- or free base porphyrin, and the nature of the solvate (i.e., guest) dramatically influence struct ural features. A one-dimensional, columnar structure is found for H2T( 3',5'-DHP)P.5EtOAc. with benzonitrile as solvate, the structure of H2T (3',5'-DHP)P.7C(6)H(5)CN changes substantially to a three-dimensional corrugated-sheet structure in order to accommodate a larger pore size. When the hydroxyl substituents are simply changed from the m- to the o-phenyl positions, an essentially two-dimensional layered structure i s formed for H2T(2',6'-DHP)P.4EtOAc. Zn[T(2',6'-DHP)P](EtOAc)(2).2EtOA c has a two-dimensional layered structure, similar to that of its free base H2T(2',6'-DHP)P interaction between the aryl rings of the adjace nt layers. The crystal structures of both Zn[T(3',5'-DHP)P] and Mn[T(3 ',5'-DHP)P](Cl) exhibited three-dimensional hydrogen-bonding features. Zn[T(3',5'-DHP)P](THP)(2).2THF.3CH(2)Cl(2) has a three-dimensional in terconnected layered structure with metalloporphyrins arranged in a sl ipped stack orientation within the layers. In the structure of Mn[T(3' ,5'DHP)P](THF)(2).Cl.2THF.5C(6)H(5)CH(3), a chloride anion dictates th e three-dimensional packing by bridging four metalloporphyrin molecule s through Cl ... HO bonding interactions. In all of these structures, large solvate-filled channels ate present with cross-sections as large as 42 Angstrom(2). The pore volumes of these channels are exceptional ly large: as much as 67% of the unit cell volume.