Synthesis, Spectra and Photophysics of some Free Base Tetrafluoroalkyl and Tetrafluoroaryl Porphyrins with Potential Applications in Imaging¶

Grancho, J. C. P.; Pereira, Mariette M.; Miguel, Maria G.; Gonsalves, A. M. Rocha

doi:10.1562/0031-8655(2002)0750249ssapos2.0.co2

Cited by 10 publications

(6 citation statements)

References 65 publications

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“…Hereby, the fluorescence intensity was found to decay strictly monoexponentially with a lifetime of 1.4 ns (see SI, Figure S7). This value is in good agreement with the existing reports on TF 5 PPs. ,,− Due to fluorescence quenching, 1 could not be probed successfully by TCSPC, yet combining the information from TCSPC and steady state fluorescence spectroscopy, the fluorescence lifetime of 1 is estimated as with τ ref as the fluorescence lifetime of the reference and Φ Fl as well as Φ ref the fluorescence quantum yields of 1 and reference, respectively. In light of the aforementioned, the estimated singlet excited state lifetime of the ZnTF 5 PP − C 60 conjugate 1 is 390 ps.…”

Section: Resultssupporting

confidence: 89%

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Efficient Low Driving Force Charge Separation in an Electron Deficient Zn-Porphyrin−Fullerene Donor–Acceptor Conjugate

et al. 2019

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Here, we present a novel conjugate based on a weakly electron-donating Zn(II)-meso-tetrakis(pentafluorophenyl)porphyrin linked to a strongly electron-accepting C 60 . From spectroscopic and electrochemical investigations a 1.9 eV high charge-separated state is derived. Transient absorption spectroscopy measurements analyzed by global target analysis confirmed the successful charge separation with a quantum yield of 72% despite an overall small driving force of only −0.2 eV. The chargeseparated state lifetime is in the nanosecond range. Considering that 90% of the singlet excited state energy is transiently stored in the charge-separated state, we conclude a charge separation energy efficiency of 65%.

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Section: Resultssupporting

confidence: 89%

“…ZnTF 5 PP and 1 possess one Q 0–1 -band absorption at 546 nm with an almost negligibly weak Q 0–0 -band absorption at 580 nm, as opposed to ∼550/595 nm absorptions and the more intense Q 0–0 -band transitions seen for ZnTPP. These differences are attributed to the electronic influence of the perfluorination of the phenyls. − …”

Section: Resultsmentioning

confidence: 99%

Efficient Low Driving Force Charge Separation in an Electron Deficient Zn-Porphyrin−Fullerene Donor–Acceptor Conjugate

et al. 2019

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“…In both cases, the formation of the complex with Zn(II) produced a hypsochromic shift of ~45 nm in comparison with free-base porphyrin. These emission bands have been assigned to Q x (0-0) and Q x (0-1) transitions [32,49]. These spectroscopic properties are characteristic of porphyrins with D 2h symmetry, indicating that the vibronic structure of the tetrapyrrolic macrocycle remains practically unchanged upon excitation [53].…”

Section: Uv-visible Spectroscopic Characterizationmentioning

confidence: 92%

“…The spectrum of the free-base porphy TPPF20 shows a Soret band at 410 nm and four Q bands between 590 and 650 nm. The electronic transitions are characteristics of porphyrins substituted in the meso-positio [49,50]. On the other hand, the UV-visible absorption spectrum of the metallated porph rin ZnTPPF20 shows a Soret band at 419 nm and two Q bands between 530 and 600 n typical of the corresponding Zn(II) substituted porphyrins [32,51].…”

Section: Uv-visible Spectroscopic Characterizationmentioning

confidence: 97%

Porphyrin Polymers Bearing N,N′-Ethylene Crosslinkers as Photosensitizers against Bacteria

et al. 2022

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The appearance of microbes resistant to antibiotics requires the development of alternative therapies for the treatment of infectious diseases. In this work two polymers, PTPPF16-EDA and PZnTPPF16-EDA, were synthesized by the nucleophilic aromatic substitution of 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin and its Zn(II) complex with ethylenediamine, respectively. In these structures, the tetrapyrrolic macrocycles were N,N′-ethylene crosslinked, which gives them greater mobility. The absorption spectra of the polymers showed a bathochromic shift of the Soret band of ~10 nm with respect to the monomers. This effect was also found in the red fluorescence emission peaks. Furthermore, both polymeric materials produced singlet molecular oxygen with high quantum yields. In addition, they were capable of generating superoxide anion radicals. Photodynamic inactivation sensitized by these polymers was tested in Staphylococcus aureus and Escherichia coli bacteria. A decrease in cell viability greater than 7 log (99.9999%) was observed in S. aureus incubated with 0.5 μM photosensitizer upon 30 min of irradiation. Under these conditions, a low inactivation of E. coli (0.5 log) was found. However, when the cells were treated with KI, the elimination of the Gram-negative bacteria was achieved. Therefore, these polymeric structures are interesting antimicrobial photosensitizing materials for the inactivation of pathogens.

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“…Particularly, porphyrin 2 bears a highly lipophilic trifluoromethyl group, which increases the amphiphilic character of the structure (23). The influence of the trifluoromethyl group in biologically active molecules is often associated with the increased lipophilicity that this substituent imparts (24–26). The spectroscopic and photodynamic properties of tricationic porphyrin 2 were changed by forming a metal complex with Pd(II) 3 (27,2).…”

Section: Introductionmentioning

confidence: 99%

Photodynamic Studies and Photoinactivation of Escherichia coli Using meso‐Substituted Cationic Porphyrin Derivatives with Asymmetric Charge Distribution^¶

Lazzeri

Rovera

Pascual

et al. 2004

Photochem & Photobiology

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The photodynamic activities of novel asymmetrically meso substituted cationic porphyrins, 5,10‐di(4‐methylphenyl)‐ 15,20‐di(4‐trimethylammoniumphenyl)porphyrin iodide 1 and 5‐(4‐trifluorophenyl)‐10,15,20‐tris(4‐trimethylammoniumphenyl)porphyrin iodide 2 and its metal complex with Pd(II) 3, have been investigated in both homogeneous medium bearing photooxidizable substrates and in vitro on a typical gram‐negative bacterium Escherichia coli. The amphiphilic character of porphyrin 2 was increased by the presence of a high‐lipophilic trifluoromethyl group and its photophysical properties changed by forming a complex with Pd(II). Absorption and fluorescence spectroscopic studies were compared in different media. Fluorescence quantum yields (øF) of 0.16 for 1 in tetrahydrofuran and 0.08 for 2 in N, N‐dimethylformamide (DMF) were calculated, whereas no significant emission was detected for Pd(II) porphyrin 3. The singlet molecular oxygen, O2(1Δ(g), production was evaluated using 9,10‐dimethylanthracene in DMF yielding relative values of 1, 0.55 and 0.47 for porphyrins 3, 2 and 1, respectively. A faster decomposition of L‐tryptophan was obtained using Pd(II) porphyrin 3 as sensitizer with respect to the free‐base porphyrins 1 and 2. In biological medium, the behavior of cationic porphyrins 1‐3 were compared with that of 5‐(4‐carboxyphenyl)‐10,15,20‐tris(4‐methylphenyl)porphyrin 4, which was used as a noncationic sensitizer. These porphyrins are rapidly bound to E. coli cells in 5 min and the amount of cell‐bound sensitizer is not appreciably changed incubating the cultures for longer times. The recovered porphyrin 2 after one washing step reaches a value of ∼2.9 nmol/106 cells and this amount remains high even after three washes, indicating that this sensitizer is tightly bound to cells. Photosensitized inactivation of E. coli was analyzed using cells without and with one washing step. In both cases, a higher photoinactivation of cells was found for tricationic porphyrin 2 and 3, causing a ‐5.5 log (99.999%) decrease of cell survival, when treated with 10 μM of sensitizer. Under these conditions, a lower effect was found for porphyrin 1 (‐4 log) whereas sensitizer 4 did not produce appreciable photodamage. The results were also confirmed by growth delay experiments. These studies show that the amphiphilic tricationic porphyrin 2 and 3 bearing a trifluoromethyl group can be a promising model for phototherapeutic agents with potential applications in inactivation of bacteria by photodynamic therapy.

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Synthesis, Spectra and Photophysics of some Free Base Tetrafluoroalkyl and Tetrafluoroaryl Porphyrins with Potential Applications in Imaging¶

Cited by 10 publications

References 65 publications

Efficient Low Driving Force Charge Separation in an Electron Deficient Zn-Porphyrin−Fullerene Donor–Acceptor Conjugate

Efficient Low Driving Force Charge Separation in an Electron Deficient Zn-Porphyrin−Fullerene Donor–Acceptor Conjugate

Porphyrin Polymers Bearing N,N′-Ethylene Crosslinkers as Photosensitizers against Bacteria

Photodynamic Studies and Photoinactivation of Escherichia coli Using meso‐Substituted Cationic Porphyrin Derivatives with Asymmetric Charge Distribution^¶

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Synthesis, Spectra and Photophysics of some Free Base Tetrafluoroalkyl and Tetrafluoroaryl Porphyrins with Potential Applications in Imaging¶

Cited by 10 publications

References 65 publications

Efficient Low Driving Force Charge Separation in an Electron Deficient Zn-Porphyrin−Fullerene Donor–Acceptor Conjugate

Efficient Low Driving Force Charge Separation in an Electron Deficient Zn-Porphyrin−Fullerene Donor–Acceptor Conjugate

Porphyrin Polymers Bearing N,N′-Ethylene Crosslinkers as Photosensitizers against Bacteria

Photodynamic Studies and Photoinactivation of Escherichia coli Using meso‐Substituted Cationic Porphyrin Derivatives with Asymmetric Charge Distribution¶

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Product

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Photodynamic Studies and Photoinactivation of Escherichia coli Using meso‐Substituted Cationic Porphyrin Derivatives with Asymmetric Charge Distribution^¶