Reactions of methylated quercetin derivatives with singlet molecular oxygen

Venediktov, E. A.; Tokareva, O. G.

doi:10.1007/bf02771416

Cited by 9 publications

(4 citation statements)

References 5 publications

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“…According to the rules for selecting sensitizer/emitter couples for PAP 3D displays, metal-phthalocyanine complexes have a wide gap between the S 0 → S 2 Soret and the S 0 → S 1 Q-bands in the absorption spectra, which could be good sensitizer candidates for PAP 3D displays. Furthermore, they have a high quantum yield of singlet oxygen and their phosphorescent emissions are in the near-infrared region [46][47][48]. Here, two metalphthalocyanine complexes, PdPrPc and PdBuPc, were selected as sensitizers.…”

Section: Resultsmentioning

confidence: 99%

Luminescent Materials for Volumetric Three-Dimensional Displays Based on Photoactivated Phosphorescence

Wan

Liu

et al. 2023

Polymers

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True three-dimensional (3D) displays are the best display technologies and their breakthrough is primarily due to advancements in display media. In this paper, we propose two luminescent materials for a static volumetric 3D display based on photoactivated phosphorescence. The luminescent materials include (1) dimethyl sulfoxide (DMSO)/1-methyl-2-pyrrolidinone (NMP) or tetramethylene sulfoxide (TMSO) as the solvent and photochemically-deoxygenating reagent; (2) a metal phthalocyanine complex as the sensitizer; (3) a phosphorescent platinum complex as the emitter. The metal phthalocyanine complex, PdPrPc (PdBuPc), absorbs the light beam of 635 nm and the solvent scavenges the sensitized singlet oxygen. Light beams pass through a deoxygenated zone. The phosphorescent emitter, PtNI, absorbs the 440 nm light beam and phosphoresces only in the deoxygenated zone generated by the sensitizer. Phosphorescent voxels and high-contrast 3D images are well-defined at the intersection of 635 and 440 nm light beams.

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Section: Resultsmentioning

confidence: 99%

Luminescent Materials for Volumetric Three-Dimensional Displays Based on Photoactivated Phosphorescence

Wan

Liu

et al. 2023

Polymers

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“…1), the ratio of γ Δ for these solvents can be found from Eq. (6): amplifier, as described in [30]. The luminescence was measured using a glass filter IKS-7 (short-wave boundary transmission at 980 nm) using a nitrogen laser as a source of photoexcitation (wavelength 337 nm, pulse energy 20 μJ, pulse duration 2 ns, repetition rate 30 Hz).…”

Section: Methodsmentioning

confidence: 99%

Solvent effect on the photogeneration of singlet molecular oxygen by copper tetra(tert-butyl)phthalocyanine

Venediktov

Tulikova

2012

Russ J Gen Chem

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The photogeneration of the singlet molecular oxygen ( 1 O 2 ) by copper tetra(4-tert-butyl) phthalocyanine in organic solvents of different nature was substantiated. The apparent quantum yields of 1 O 2 in benzene and pyridine were determined. The data obtained indicate an influence of the coordinating properties of the solvent on the 1 O 2 yield. However, this factor is not "critical" as in the case of photogeneration of 1 O 2 by copper tetra(5-tert-butylpyrazino)porphyrazine.The interest in the photogeneration of singlet molecular oxygen ( 1 O 2 , 1 Δ g ) by phthalocyanines is due to their application in a number of photochemical and photomedical technologies [1][2][3][4].A photogeneration of 1 O 2 by phthalocyanines proceeds as a quenching of their excited triplet states by O 2 ( 3 Σ g -) molecules through the mechanism of energy transfer [2,5], and depends on both intramolecular (the macroheterocycle structure, the central atom nature) and external (solvation, aggregation) factors. As to copper phthalocyanine, the published data on the effectiveness of this process are contradictory. Usually this situation is attributed to a tendency of copper phthalocyanine to aggregation (see, for example, [2]). However, in [6] by an example of the 1 O 2 photogeneration by copper tetra(5-tert-butylpyrazino)porphyrazine it has been shown that the important external factors affecting the yield of 1 O 2 may include the coordinating ability of the solvent. This effect is apparently due to the competitive quenching of excited triplet molecules of the sensitizer by the solvent due to its axial coordination [7-10].The purpose of this study is to investigate the influence of the coordinating ability of solvent on the photogeneration of 1 O 2 by copper phthalocyanine by an example of behavior in the process of copper tetra-(4-tert-butyl)phthalocyanine [(t-Bu) 4 PcCu], the most convenient object for this purpose owing to its good solubility in many organic media.The electron absorption spectrum of the (t-Bu) 4 PcCu solutions is typical of most metallphthalocyanines, with an intense Q-band at 670-680 nm [11,12]. The band position depends on the solvent. In benzene, the band maximum (λ Q ) occurs at 677.5 (±0.5) nm, and its decimal molar absorption coefficient is equal to 1.7×10 5 (±0.2×10 5 ) cm -1 mol -1 l. With the increase in the solvent refractive index, the λ Q value undergoes a red shift (Fig. 1). These data can be interpreted within the framework of universal solvation of (t-Bu) 4 PcCu [13].A good qualitative example of photochemical activity of (t-Bu) 4 PcCu is its ability to sensitize the photooxidation of the 1 O 2 acceptors. The results of one such experiment on the sensitized photobleaching of tetracene solution in pyridine are shown in Fig. 2. Similar results were obtained with the other, less basic, solvents. Accounting for the oxidative nature of this process, whose mechanism has been substantiated in detail in [14][15][16], these data allow a preliminary

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“…Схема установки и методика измерений описа-ны в работах. [10,11] Время жизни 1 О 2 (τ) находили из кривых затухания его люминесценции в области 1270 нм по уравнению…”

Section: (1)3(2)-бис(nnn-триметиламинометилиодид)хлорин E 6 13(1)unclassified

“…Тогда, в при-ближении метода конкурирующих реакций [25] значение k r можно вычислить из экспериментально измеренных величин по формуле k эф.т /k эф = k r,т /k r (8) Поскольку известно, [26] что k r,т =5.2•10 7 л/(моль·с), из уравнения (8) следует, что k r составляет (2±0.4)•10 4 л/(моль·с). Эта величина одного порядка с константа-ми скорости аналогичной реакции других производных хлорина е 6 .…”

Section: результаты и обсуждениеunclassified

Synthesis, Spectral, Luminescence and Photochemical Properties of the Chlorin е6 Tricationic Derivative with Trimethylammonio Groups

Venediktov¹,

Tulikova²,

Rozhkova³

et al. 2017

MHC

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Reactions of methylated quercetin derivatives with singlet molecular oxygen

Cited by 9 publications

References 5 publications

Luminescent Materials for Volumetric Three-Dimensional Displays Based on Photoactivated Phosphorescence

Luminescent Materials for Volumetric Three-Dimensional Displays Based on Photoactivated Phosphorescence

Solvent effect on the photogeneration of singlet molecular oxygen by copper tetra(tert-butyl)phthalocyanine

Synthesis, Spectral, Luminescence and Photochemical Properties of the Chlorin е6 Tricationic Derivative with Trimethylammonio Groups

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