Tetraoxaporphycen‐Dikation

Vogel, Emanuel; Sicken, Martin; Röhrig, Peter; Schmickler, Hans; Lex, Johann; Ermer, Otto

doi:10.1002/ange.19881000341

Cited by 39 publications

(18 citation statements)

References 29 publications

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“…The signal for the NH protons in 1 a was significantly shifted downfield to d = 5.5 ppm with those of the bridge head protons. To confirm the structure of dodecaA C H T U N G T R E N N U N G alkyl-substituted porphycene, bicycloA C H T U N G T R E N N U N G [2.2.2]octene-fused porphycene (11) was prepared, in which the double bonds of the BCOD moieties were reduced (see the Experimental Section for the synthetic details of 11.) For comparison, the 1 H NMR spectrum of 11 is shown in Figure 4 c. The inner NH protons were observed at d = 5.6 ppm and ethyl signals were clearly observed at d = 4.4 and 1.8 ppm.…”

Section: Resultsmentioning

confidence: 99%

“…Tuning of the electronic properties of porphycenes has been only attempted by introducing b substituents, [7] meso substituents, [8] p expansion, [9,10] and core modification. [11] This is mainly owing to the difficulty of introducing more than two meso substituents into b-octasubstituted porphycenes. [12] Herein, we report the first synthesis of dodecasubstituted porphycenes 1 by taking advantage of the unique features of bicycloA C H T U N G T R E N N U N G [2.2.2]octadiene (BCOD)-fused 2,2'-bipyrroles.…”

Section: Introductionmentioning

confidence: 99%

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First Synthesis of Dodecasubstituted Porphycenes

Kuzuhara

Yamada

Yano

et al. 2011

Chemistry A European J

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The synthesis of dodecasubstituted porphycenes has not been reported, to date. Herein, the preparation of tetramethyloctaethylporphycene by a McMurry-type coupling of 3,3',4,4'-tetraethyl-5,5'-diformyl-2,2'-bipyrrole was attempted at first, but dodecasubstituted porphycene was not successfully obtained and only pyrrolocyclophene was obtained. The structure of the pyrrolocyclophene was determined by (1)H NMR spectroscopy, FAB MS, and X-ray crystal-structure analysis. The pyrrolocyclophene was not successfully oxidized to porphycene. Then, the McMurry-type coupling of bicyclo[2.2.2]octadiene (BCOD)-fused 5,5'-diacyl-2,2'-bipyrroles was performed and tetra-meso-octa-β-substituted (dodecasubstituted) porphycenes were successfully obtained for the first time. The structures were determined by (1)H NMR spectroscopy and X-ray crystal-structure analysis. The crystal structures and NMR spectra were compared carefully with octasubstituted porphycenes, and there was a good correlation between the position of the substituents, the N1−−N2 and N1−−N4 distances of the porphycene inner nitrogen atoms, and NMR chemical shifts of the inner NH protons, which expressed the strength of N−−H⋅⋅⋅N hydrogen bonding between N1 and N2. These results suggested that the BCOD structure was relatively compact compared with common alkyl groups and that was why the dodecasubstituted porphycenes were available this time. UV/Vis absorption and fluorescence properties are also discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

First Synthesis of Dodecasubstituted Porphycenes

Kuzuhara

Yamada

Yano

et al. 2011

Chemistry A European J

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“…Thus, the perchlorate salt of the tetraoxaporphycene dication (34) [150], the 21,23-dithiaporphycene (35) [115], the brominated tetrasulfido [20]annulene (36) [151], and the tetraazatetrathia[20]-annulene (37) [117] have been reported (Scheme 3).…”

Section: Peripheral Functionalization 233 Modification Of the Corementioning

confidence: 97%

Porphycenes: Facts and Prospects in Photodynamic Therapy of Cancer

Stockert¹,

Cañete²,

Juarranz³

et al. 2007

CMC

177

130

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The photodynamic process induces cell damage and death by the combined effect of a photosensitizer (PS), visible light, and molecular oxygen, which generate singlet oxygen ((1)O(2)) and other reactive oxygen species that are responsible for cytotoxicity. The most important application of this process with increasing biomedical interest is the photodynamic therapy (PDT) of cancer. In addition to hematoporphyrin-based drugs, 2nd generation PSs with better photochemical properties are now studied using cell cultures, experimental tumors and clinical trials. Porphycene is a structural isomer of porphyrin and constitutes an interesting new class of PS. Porphycene derivatives show higher absorption than porphyrins in the red spectral region (lambda > 600 nm, epsilon > 50000 M-(1)cm(-1)) owing to the lower molecular symmetry. Photophysical and photobiological properties of porphycenes make them excellent candidates as PSs, showing fast uptake and diverse subcellular localizations (mainly membranous organelles). Several tetraalkylporphycenes and the tetraphenyl derivative (TPPo) induce photodamage and cell death in vitro. Photodynamic treatments of cultured tumor cells with TPPo and its palladium(II) complex induce cytoskeletal changes, mitotic blockage, and dose-dependent apoptotic or necrotic cell death. Some pharmacokinetic and phototherapeutic studies on experimental tumors after intravenous or topical application of lipophilic alkyl-substituted porphycene derivatives are known. Taking into account all these features, porphycene PSs should be very useful for PDT of cancer and other biomedical applications.

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“…[2,6,[18][19][20][21][22] For instance, a porphycene molecule (8) imprints an [18]annulene frame of C 2h symmetry (7). [18,23] On the other hand, [18]annulene 4 itself is not just a trivial standard of aromaticity, but a fluxional molecule, affected by steric interactions of internal protons. [24,25] Although an [18]annulene complies with the spectral and structural criteria of aromaticity, as a consequence of the conformational flexibility it is a relatively reactive molecule, which decomposes at elevated temperatures with the tendency for addition/polymerization rather than electrophilic substitution reactions.…”

Section: Introductionmentioning

confidence: 99%

A Flexible Porphyrin–Annulene Hybrid: A Nonporphyrin Conformation formeso‐Tetraaryldivacataporphyrin

Pacholska‐Dudziak¹,

Szterenberg²,

Latos‐Grażyński³

2011

Chemistry A European J

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An annulene-porphyrin hybrid, the diaaza-deficient porphyrin 5,10,15,20-tetraaryl-21,23-divacataporphyrin, has been synthesized by an extrusion of tellurium atom(s) from 5,10,15,20-tetraaryl-21,23-ditelluraporphyrin under treatment with HCl. In addition, a monoaza-deficient 5,10,15,20-tetraaryl-21-tellura-23-vacataporphyrin was formed in the same reaction. The two new members of the vacataporphyrin family were characterized by X-ray crystallography, as well as UV/Vis and NMR spectroscopy. These aromatic molecules preserve the fundamental structural and spectroscopic features of the parent tetraarylporphyrin. The X-ray crystal structures of 21,23-divacataporphyrin and 21-tellura-23-vacataporphyrin show typical porphyrin patterns. The molecules are not strictly planar and show distortion of the annulene moieties. The N22⋅⋅⋅N24 distances (5.23 and 5.09 Å) are considerably longer than in regular porphyrins. For 21,23-divacataporphyrin, variable-temperature (1)H NMR spectroscopy data allowed the identification of divacataporphyrin stereoisomers differentiated by the geometry of the butadiene bridges. The forms remain in thermodynamic equilibrium.

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Tetraoxaporphycen‐Dikation

Abstract: hand der charakteristischcn roten Fluorcszeni (hci Anregung mit Licht der Wellcnlinge 366 nm) des Dikations 4 leicht lokalisiert wcrden.[ 101 Die (vorllufig)

Cited by 39 publications

References 29 publications

First Synthesis of Dodecasubstituted Porphycenes

First Synthesis of Dodecasubstituted Porphycenes

Porphycenes: Facts and Prospects in Photodynamic Therapy of Cancer

A Flexible Porphyrin–Annulene Hybrid: A Nonporphyrin Conformation formeso‐Tetraaryldivacataporphyrin

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