Synthesis and characterization of new non-aromatic texaphyrin-type expanded porphyrins

✍ Scribed by SYLVIE MEYER; MICHAEL C. HOEHNER; VINCENT LYNCH; JONATHAN L. SESSLER

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 133 KB
• Volume: 03
• Category: Article
• ISSN: 1088-4246
• DOI: 10.1002/(sici)1099-1409(199902)3:2<148::aid-jpp111>3.0.co;2-o

✦ Synopsis

The synthesis and X-ray diffraction-based characterization of a texaphyrin-type non-aromatic expanded porphyrin, 13,18,22,27-tetraethyl-14,17,23,26-tetramethyl-20-p-nitrophenyl-3,10,28,29,30,31-hexaazahexacyclo[23.2.1.0^4,9^.1^12,15^.1^16,19^.1^21,24^]untriaconta-2, 4, 5, 7, 10,12,14,16,18,-20,22,24(30),25,27-tetradecaene (1), is reported. This Schiff base macrocycle was prepared in good yield via the 1:1 HCl -catalyzed condensation of a tetrapyrrole dialdehyde precursor, (di(5-formyl-4,4'-diethyl-3,3'-dimethyl-2,2'-bipyrrole)-p-nitrophenylmethine), with 1,2-phenylenediamine. Compound 1 was assigned as being a 26 π-electron non-aromatic benzannulene on the basis of both proton NMR and single-crystal X-ray diffraction analyses. The latter studies, in particular, revealed a non-planar macrocyclic structure co-crystallized with a molecule of water. By varying either the diamine used in the cyclization step and/or the substituent in the meso-position of the tetrapyrrolic precursor, a range of other systems analogous to 1 could be obtained. The resulting systems were found to present good stability both in the solid state and in solution.