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. 2009 Nov 2;48(21):10346-57.
doi: 10.1021/ic9014866.

6-Azahemiporphycene: a new member of the porphyrinoid family

Federica Mandoj  1 , Sara Nardis, Giuseppe Pomarico, Manuela Stefanelli, Luca Schiaffino, Gianfranco Ercolani, Luca Prodi, Damiano Genovese, Nelsi Zaccheroni, Frank R Fronczek, Kevin M Smith, Xiao Xiao, Jing Shen, Karl M Kadish, Roberto Paolesse
Affiliations

6-Azahemiporphycene: a new member of the porphyrinoid family

Federica Mandoj et al. Inorg Chem. .

Abstract

The reaction of 5,10,15-triarylcorrole with 4-amino-4H-1,2,4-triazole provides another example of corrole ring expansion to give the corresponding 6-azahemiporphycene, a novel porphyrin analogue. The facile oxidation of the corrole ring is a required step for the ring expansion and for this reason the reaction fails in the case of corroles bearing meso-phenyl groups carrying electron-withdrawing substituents. Steric requirements also limited the scope of the reaction, which is not successful in the case of 2,6-disubstituted meso-aryl corroles. The occurrence of an initial oxidation is further supported by formation of the 6-azahemiporphycene derivative when the reaction is carried out under the same conditions, using a 5- or a 10-isocorrole as starting material. (1)H NMR spectra and X-ray crystal characterization of 6-azahemiporphycene evidenced the presence of an intramolecular N-H...N hydrogen bond in the inner core of the macrocycle, while photophysical characterization confirmed the aromatic character of the novel macrocycle, showing an intense Soret-like band around 410 nm in the absorption spectrum. The fluorescence emission is very modest, and 6-azahemiporphycene showed higher photostability than the corresponding corrole species. Different metal complexes of 6-azahemiporphycene were prepared following synthetic protocols usually exploited for the preparation of metalloporphyrins, demonstrating good coordination properties for the macrocycle. Both the free-base and metal derivatives were characterized by cyclic voltammetry and spectroelectrochemistry in dichloromethane and benzonitrile. To further detail the behavior of this novel macrocycle, density functional theory (DFT) calculations were carried out on the basic structure of 6-azahemiporphycene with the aim of assessing aromaticity and tautomerism, as well as calculating its stability with respect to the 5-aza isomer.

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Figures

Figure 1
Figure 1
Molecular structure of 11.
Figure 2
Figure 2
Molecular structure of 20.
Figure 3
Figure 3
Molecular structures of 23 and 24 isocorroles.
Figure 4
Figure 4
UV—vis spectral variations of 12 upon addition of 1 equiv of triflic acid (solid line). Addition of 1 equiv of tributylamine restores the original spectrum (dashed line).
Figure 5
Figure 5
Emission spectrum of 12 before (solid line) and after (dashed line) addition of 1 equiv of triflic acid.
Figure 6
Figure 6
UV-vis absorption (solid line) and emission (dashed line) spectrum of Zn complex 18.
Figure 7
Figure 7
Basic structure of 6-azahemiporphycene 25.
Figure 8
Figure 8
Cyclic voltammograms of M-6-aza-5,11,16-tris(4-terf-butyl-phenyl)hemiporphycene in PhCN containing 0.1 M TBAP where M and the compound number are indicated in the figure.
Figure 9
Figure 9
UV-visible spectral changes during the first reduction of (a) MnIIICl and (b) CuII azahemiporphycenes in PhCN, 0.1 M TBAP.
Figure 10
Figure 10
UV–visible spectral changes of CoII azahemiporphycene 15 during (a) the first oxidation at 0.70 V and (b) the first reduction at −1.10 V inPhCN,0.1M TBAP.
Scheme 1
Scheme 1
Reaction Pathway for the 6-Azahemiporphycene Formation
Figure 12
Figure 12
Chart 1
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References

    1. Kadish KM, Smith KM, Guilard R, editors. The Porphyrin Handbook. 1–10 Academic Press; San Diego, CA: 2000.
    2. Kadish KM, Smith KM, Guilard R, editors. The Porphyrin Handbook. 11–20 Academic Press; San Diego, CA: 2003.
    1. Drain CM, Hupp JT, Suslick KS, Wasielewski MR, Chen XJ. Porphyrins Phthalocyanines. 2002;6:243–258.
    1. Sessler JL, Weghorn SJ. Expanded, Contracted and Isomeric Porphyrins. Pergamon; Oxford: 1997.
    2. Jasat A, Dolphin D. Chem Rev. 1997;97:2267–2340. - PubMed
    3. Sessler JL, Gebauer A, Vogel E. In: The Porphyrin Handbook. Kadish KM, Smith K, Guilard R, editors. Vol. 2. Academic; San Diego, CA: 2000. pp. 1–54.
    4. Sessler JL, Gebauer A, Weghorn SJ. In: The Porphyrin Handbook. Kadish KM, Smith K, Guilard R, editors. Vol. 2. Academic; San Diego, CA: 2000. pp. 55–124.
    5. Sessler JL, Seidel D. Angew Chem, Int Ed. 2003;42:5134–5175. - PubMed
    6. Misra R, Chandrashekar TK. Acc Chem Res. 2008;41:265–279. - PubMed
    7. Callot HJ, Rohrer A, Tschamber Th. New J Chem. 1995;19:155–159.
    1. Horn S, Dahms K, Senge MO. J Porphyrins Phthalocyanines. 2008;12:1053–1077.
    2. Jux N. Angew Chem, Int Ed. 2009;48:4284–4286. - PubMed
    1. Callot H. Dalton Trans. 2008:6346–6357. - PubMed
    2. Senge MO, Sergeeva NN. Angew Chem, Int Ed. 2006;45:7492–7495. - PubMed

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