Tetraoxa [24] porphyrinogen(4.0.4.0)/tetraoxa[22]porphyrin(4.0.4.0) dication a further isomer of the aromatic 22π-tetraoxaporphyrins

Autor: Markus Hafner, Jörg Daub, Michael Porsch, Fritz Kastner, Gottfried Märkl, Thomas Burgemeister, Peter Kreitmeier
Rok vydání: 1996
Předmět:
Zdroj: Tetrahedron. 52:1981-1996
ISSN: 0040-4020
DOI: 10.1016/0040-4020(95)01041-6
Popis: While the antiaromatic tetraoxa[24]porphyrinogen(2.2.2.2) 1 ( trans , cis , trans , cis ) and the corresponding aromatic dication 1 2+ have been published recently, the synthesis of the title compounds is described for the first time. Beside the cis , trans , cis , trans -tetraoxa[24]porphyrinogen(4.0.4.0) 2b the isomeric porphyrinogens 2a ( trans , cis , cis , trans ) and 2c ( all - trans in the cisoid conformation) could be isolated. The tetraoxa[22]porphyrin(4.0.4.0) dication is an aromatic 22π-system, it exists only in the cis , trans , cis , trans -configuration. The dication 2b 2+ can be reduced with tetrakis-N,N-dimethylaminoethene to give pure porphyrinogen 2b . The electrochemistry of the system 2/ 2b 2+ and AM1 calculations are described.
Databáze: OpenAIRE
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