Aryl nitroporphycenes and derivatives: first regioselective synthesis of dinitroporphycenes

Anguera, Gonzalo; Llinàs, Maria C.; Batllori, Xavier; Sánchez‐García, David

doi:10.1142/s1088424611003744

Cited by 10 publications

(9 citation statements)

References 23 publications

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“…The absorption pattern characteristic for 122 is essentially preserved in derivatives with various substituents on the phenyl group, namely, 126 , 128 , 129 , and 130 and 131 , and for meso -dinitro derivatives 132 and 133 . It is also maintained in temocene ( 134 , Scheme ), the porphycene analogue of temoporfin (Foscan), a commercially available photosensitizer in PDT.…”

Section: Electronic Spectroscopymentioning

confidence: 99%

“…92 The absorption pattern characteristic for 122 is essentially preserved in derivatives with various substituents on the phenyl group, namely, 126, 93 128, 94 129, 95 and 130 and 131, 96 and for meso-dinitro derivatives 132 and 133. 97 It is also maintained in temocene (134, Scheme 23), 98 the porphycene analogue of temoporfin (Foscan), a commercially available photosensitizer in PDT. Temocene and its derivatives, 135, 98 136 and 137, 99 and 138, 100,101 are promising in PDT because of their stronger absorption, higher photostability, and lower dark toxicity compared to temoporfin.…”

Section: Electronic Spectroscopy 21 Absorption Spectramentioning

confidence: 99%

“…The effect of substitution at the meso positions on the absorption strongly depends on the substituent: It is weak for the acetoxy group (123), 103 moderate for the nitro (124, 103 132 and 133) 97 and amide (127, 97 128 94 ) derivatives, and very strong for the amino substitution (125). 103 Calculations of fluorescence properties in the red and near-IR regions (Figure 4).…”

Section: Electronic Spectroscopy 21 Absorption Spectramentioning

confidence: 99%

“…Most porphycenes exhibit fluorescence quantum yields at least on the order of a few percent or higher. Those that do not can be rapidly deactivated in S 1 for various reasons: (a) nonplanarity (75,76,80,96,97,169,170), associated with the conical intersection along the excited-state trans−cis2 tautomerization path, as described in more detail in section 3.1.1; (b) low-lying S 1 state (169, 170, 186) (energy-gap law); or (c) specific interactions with the solvent (137,138). The low fluorescence quantum yields of Pd and Cu complexes of 122 might be due to a heavy-atom effect, but it is rather surprising that the triplet formation efficiency of 122-Cu is only 0.35.…”

Section: Fluorescence and Other Energy Relaxation Channelsmentioning

confidence: 99%

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Spectroscopy and Tautomerization Studies of Porphycenes

2016

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Tautomerization in porphycenes, constitutional isomers of porphyrins, is strongly entangled with spectral and photophysical parameters. The intramolecular double hydrogen transfer occurring in the ground and electronically excited states leads to uncommon spectroscopic characteristics, such as depolarized emission, viscosity-dependent radiationless depopulation, and vibrational-mode-specific tunneling splittings. This review starts with documentation of the electronic spectra of porphycenes: Absorption and magnetic circular dichroism are discussed, together with their analysis based on the perimeter model. Next, photophysical characteristics are presented, setting the stage for the final part, which discusses the developments in research on tautomerism. Porphycenes have been studied in different experimental regimes: molecules in condensed phases, isolated in supersonic jets and helium nanodroplets, and, recently also on the level of single molecules investigated by optical and scanning probe microscopies. Because of the rich and detailed information obtained from these diverse investigations, porphycenes emerge as very good models for studying the complex, multidimensional phenomena involved in the process of intramolecular double hydrogen transfer.

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Section: Electronic Spectroscopymentioning

confidence: 99%

Section: Electronic Spectroscopy 21 Absorption Spectramentioning

confidence: 99%

Section: Electronic Spectroscopy 21 Absorption Spectramentioning

confidence: 99%

Section: Fluorescence and Other Energy Relaxation Channelsmentioning

confidence: 99%

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Spectroscopy and Tautomerization Studies of Porphycenes

2016

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“…It has a saddle structure with the inner hydrogens pointing out from the porphycene ring due to steric effects. Figure 2c is a meso-dinitro substituted porphycene with a planar porphycene ring that has been synthesized by Anguera et al 27,56 The synthesized dinitroporphycene had phenyl substituents at the β positions of the four pyrrolic rings, whereas in the calculations we replaced the phenyl groups with hydrogens. The trans conformer of the inner hydrogen is 3.2 kcal/mol lower in energy than the cis one.…”

Section: Molecular Structures and Nomenclaturementioning

confidence: 99%

Aromatic Pathways in Porphycene Derivatives Based on Current-Density Calculations

Benkyi

Sundholm

2018

J. Phys. Chem. A

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Magnetically induced current densities have been calculated for porphycenes at the density functional theory (DFT) level using gauge-including atomic orbitals to ensure gauge-origin independence and a fast basis-set convergence of the current densities. The current densities have been analyzed by using the gauge-including magnetically induced current (GIMIC) method. The porphycenes are aromatic sustaining strong diatropic ring currents. The ring-current pathways have been determined by integrating the strength of the current density passing selected bonds. The calculations show that the ring current of the porphycenes splits into an outer and inner branch at the pyrrolic rings implying that the ring current involves all 26 π electrons of the porphycenes, which is similar to the ring current of porphyrins. The pyrrolic rings of the aromatic porphycenes do not sustain any significant local ring currents. Dihydroporphycene with four inner hydrogens is antiaromatic with weakly aromatic pyrrolic rings. The annelated benzoic rings in benzoporphycene sustain local paratropic ring-currents, whereas the global ring current of dibenzoporphycene splits into an outer and inner branch at the benzoic rings. Comparison of calculated 1 H NMR shieldings with ringcurrent strengths shows that interactions between the inner hydrogen and the neighbor nitrogen is more significant for differences in the 1 H NMR shieldings than variations in global ring-current strengths. Calculated excitation energies show that the antiaromatic dihydroporphycene has a smaller optical gap than the aromatic porphycene, even though its HOMO-LUMO gap is larger. 1 Introduction Vogel et al. performed systematic studies of novel kinds of aromatic porphyrin structures in the mid-1980s, which led to the discovery of porphycene. 1 Porphycenes are a class of compounds that is reminiscent of porphyrin with four linked pyrrolic rings forming a central 16-membered macroring and an outer annulene ring with 20π electrons. Waluk et al. showed later that the electronic structure and the aromatic properties of porphycenes can

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Porphycenes and Related Isomers: Synthetic Aspects

Anguera

Sánchez‐García

2016

Chem. Rev.

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Porphyrins, called the pigments of life, have been studied for decades. However, the first constitutional isomer of porphyrin, porphycene, was not synthesized until 1986. This milestone marked the beginning of a new era in the field of porphyrinoids and presented opportunities for the creation of an abundance of new pigments. The unique structural and electronic features of these compounds give rise to interesting physical and optical properties with applications in biomedicine and materials science. This review focuses on the synthetic methodologies available for the preparation of porphycenes (functionalized porphycenes, extended porphycenes, benzoporphycenes, naphthoporphycenes, and heteroanalogues) and the other known isomers, namely, corrphycene, hemiporphycene, and isoporphycene. Although the classical synthetic approaches are discussed, particular emphasis is placed on improvements to the known methodologies and recent advances in the field.

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Aryl nitroporphycenes and derivatives: first regioselective synthesis of dinitroporphycenes

Cited by 10 publications

References 23 publications

Spectroscopy and Tautomerization Studies of Porphycenes

Spectroscopy and Tautomerization Studies of Porphycenes

Aromatic Pathways in Porphycene Derivatives Based on Current-Density Calculations

Porphycenes and Related Isomers: Synthetic Aspects

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