Unique protonation behavior of cationic free-base porphyrins in the interlayer space of transparent solid films comprising layered α-zirconium phosphate

Fujimura, Takuya; Aoyama, Yu-hei; Sasai, Ryo

doi:10.1016/j.tetlet.2019.07.003

Cited by 9 publications

(8 citation statements)

References 21 publications

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“…This absorption spectral change of DMATMPyP by pH could be explained by the protonation of the DMA moiety and the central pyrrole nitrogen atoms. 37 Analysis of the relationship between absorbance and pH ( Figure 3 ) was performed using a method similar to that in previous reports ( Supporting Information ). 22 The obtained p K a values were 4.5 and 2.1.…”

Section: Resultsmentioning

confidence: 99%

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Photooxidation Activity Control of Dimethylaminophenyl-tris-(N-methyl-4-pridinio)porphyrin by pH

et al. 2020

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To control the activity of photodynamic agents by pH, an electron donor-connecting cationic porphyrin, meso -( N′ , N′ -dimethyl-4-aminophenyl)-tris( N -methyl- p -pyridinio)porphyrin (DMATMPyP), was designed and synthesized. The photoexcited state (singlet excited state) of DMATMPyP was deactivated through intramolecular electron transfer under a neutral condition. The p K a of the protonated DMATMPyP was 4.5, and the fluorescence intensity and singlet oxygen-generating activity increased under an acidic condition. Furthermore, the protonation of DMATMPyP enhanced the biomolecule photooxidative activity through electron extraction. Photodamage of human serum albumin (HSA) was observed under a neutral condition because a hydrophobic HSA environment can reverse the deactivation of photoexcited DMATMPyP. However, an HSA-damaging mechanism of DMATMPyP under a neutral condition was explained by singlet oxygen production. Therefore, it is indicated that the protein photodamaging activity of DMATMPyP goes into an OFF state under a neutral hypoxic condition. Under an acidic condition, the HSA photodamaging quantum yield by DMATMPyP through electron extraction could be preserved in the presence of a singlet oxygen quencher. Photooxidation of nicotinamide adenine dinucleotide by DMATMPyP was also enhanced under an acidic condition. This study demonstrated the concept of using pH to control photosensitizer activity via inhibition of the intramolecular electron transfer deactivation and enhancement of the oxidative activity through the electron extraction mechanism. Specifically, biomolecule oxidation through electron extraction may play an important role in photodynamic therapy to treat tumors under a hypoxic condition.

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Section: Resultsmentioning

confidence: 99%

“…Indeed, a similar p K a value of the central nitrogen atoms has been reported in the case of a similar porphyrin. 37 …”

Section: Resultsmentioning

confidence: 99%

Photooxidation Activity Control of Dimethylaminophenyl-tris-(N-methyl-4-pridinio)porphyrin by pH

et al. 2020

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“…In a recent study, Fujimura et al explored the protonation behaviour of TMPyP molecules intercalated in α-ZrP films. [225] The authors found that the pyrrole groups from the porphyrins in the hybrids are protonated in HCl solution, thus leading to a colour change of the film, from yellow to greenish yellow; this change occurred at lower HCl concentration than the colour change observed by the protonation of TMPyP in solution. After calculating the pKa values of the porphyrin in the hybrid, the authors concluded that the pyrrole groups from the porphyrin were protonated at higher pH than in aqueous solution, probably due to the H + concentration caused by the high acid dissociation constant of phosphate sites on the surface of the α-ZrP sheets.…”

Section: Functionalization Of Alternative 2d Materials Using Porphyrinsmentioning

confidence: 99%

Functionalization of Graphene Oxide with Porphyrins: Synthetic Routes and Biological Applications

2020

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Among the available carbon nanomaterials, graphene oxide (GO) has been widely studied because of the possibility of anchoring different chemical species for a large number of applications, including those requiring water‐compatible systems. This Review summarizes the state‐of‐the‐art of synthetic routes used to functionalize GO, such as those involving multiple covalent and non‐covalent bonds to organic molecules, functionalization with nanoparticles and doping. As a recent development in this field, special focus is given to the formation of nanocomposites comprising GO and porphyrins, and their characterization through spectroscopic techniques (such as UV‐Vis, fluorescence, Raman spectroscopy), among others. The potential of such hybrid systems in targeted biological applications is also discussed, namely for cancer therapies relying on photodynamic and photothermal therapies and for the inhibition of telomerase enzyme. Lastly, some promising alternative materials to GO are presented to overcome current challenges of GO‐based research and to inspire future research directions in this field.

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“…On the other hand, Shi et al reported that fluorescein intercalated in layered double hydroxide exhibited a rapid optical response depending on the pH of the aqueous solution [ 14 ]. Researchers have also investigated the photoluminescence (PL) properties of luminous dyes incorporated into ion-exchangeable layered inorganic compounds modified by amphiphilic molecules in the presence of various molecules [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. For example, for rhodamine 6G dyes, the changes in PL with respect to the change in wetness, when these dyes were incorporated into laponite modified by alkyltrimethylammonium, were found to depend on the alkyl-chain length [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

“…This behavior can be explained by the intramolecular cyclization reaction from cationic rhodamine 3B (luminous type) to lactone-type rhodamine 3B (non-luminous type), which could have been induced by increases in pH around the rhodamine 3B molecules incorporated in interlayer space. Meanwhile, the p K a values of cationic free-base porphyrin were reported to be remarkably varied by intercalation into the interlayer of layered α-zirconium phosphate [ 17 ]. Researchers also investigated the PL properties of anionic fluorescein dye (AFD) incorporated into the interlayer space of layered double hydroxide (LDH) with 1-butanesulfonate (C4S) under various relative humidity (RH) conditions.…”

Section: Introductionmentioning

confidence: 99%

Photoluminescence Gas Sensing by Fluorescein-Dye Anions/1-Butanesulfonate/Layered Double Hydroxide Hybrid Materials under Humid Environment Conditions

2021

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In this study, we investigated the photoluminous spectroscopic behavior of hybrid powder incorporating both anionic fluorescein dye (AFD) and 1-butanesulfonate (C4S) with layered double hydroxide (LDH) in the presence of NH3 or NO2 gas under various relative humidity conditions. In the presence of NH3 gas, drastic photoluminescence enhancement from the LDH/AFD/C4S hybrid was observed at relative humidity (RH) ≥ 40% when the NH3 reached a certain concentration. Meanwhile, the LDH/AFD/C4S hybrid was exposed to NO2 gas at various relative humidity conditions, and the following behavior was observed: At RH ≥ 60%, the photoluminescence (PL) intensity from the hybrid gradually decreased as NO2 concentration increased. Therefore, the LDH/AFD/C4S hybrid investigated in this study is inferred to be suitable for optical NH3/NO2 sensor devices, which can be used in humid air.

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Unique protonation behavior of cationic free-base porphyrins in the interlayer space of transparent solid films comprising layered α-zirconium phosphate

Cited by 9 publications

References 21 publications

Photooxidation Activity Control of Dimethylaminophenyl-tris-(N-methyl-4-pridinio)porphyrin by pH

Photooxidation Activity Control of Dimethylaminophenyl-tris-(N-methyl-4-pridinio)porphyrin by pH

Functionalization of Graphene Oxide with Porphyrins: Synthetic Routes and Biological Applications

Photoluminescence Gas Sensing by Fluorescein-Dye Anions/1-Butanesulfonate/Layered Double Hydroxide Hybrid Materials under Humid Environment Conditions

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