Abstract
Symmetrically substituted octahydroxy polphyrins, tetrakis(3',5'-dihydroxyphenyl)porphyrin H2T(3',5'-DHP)P, tetrakis(2',6'-dihydroxyphenyl)porphyrin H2T(2',6'-DHP)P, and their Zn(II) and Mn(III) derivatives have been developed as building blocks for supramolecular hydrogen-bonded networks. The crystal structures of a series of these porphyrins exhibit unique structural features through assembly of porphyrin networks by means of directional hydrogen bonding. The position of the peripheral hydroxyl groups, the choice of metallo- or free base porphyrin, and the nature of the solvate (i.e., guest) dramatically influence structural 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·7C6H5CN 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 is formed for H2T(2',6'-DHP)P·4EtOAc. Zn[T(2',6'-DHP)P](EtOAc)2·2EtOAc 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 adjacent 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](THF)2·2THF·3CH2Cl2 has a three-dimensional interconnected layered structure with metalloporphyrins arranged in a slipped stack orientation within the layers. In the structure of Mn[T(3',5'-DHP)P](THF)2.Cl·2THF·5C6H5CH3 a chloride anion dictates the three-dimensional packing by bridging four metalloporphyrin molecules through Cl···HO bonding interactions. In all of these structures, large solvate-filled channels are present with cross-sections as large as 42 Å2. The pore volumes of these channels are exceptionally large: as much as 67% of the unit cell volume.
Original language | English (US) |
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Pages (from-to) | 8492-8502 |
Number of pages | 11 |
Journal | Journal of the American Chemical Society |
Volume | 119 |
Issue number | 36 |
DOIs | |
State | Published - Sep 10 1997 |
ASJC Scopus subject areas
- Catalysis
- General Chemistry
- Biochemistry
- Colloid and Surface Chemistry