Photochemical reactions between 1,4-benzoquinone and O2•−

Zhu, Mengyu; Lü, Jun; Hu, Yadong; Liu, Ying; Hu, Shuheng; Zhu, Chengzhu

doi:10.1007/s11356-020-09422-8

Cited by 70 publications

(28 citation statements)

References 56 publications

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“…However, there was an abrupt decrease in conversion of 16 % and 22 % by the use of methanol as the photo-generated holes (h + ) scavenger and AgNO 3 as photo-generated electrons (e À ) scavenger [58] to suppress the photocatalytic oxidation of benzyl alcohol, indicating the photo-generated electrons and photo-generated holes are active parts in the catalytic process. The role of superoxide radical (O 2 À ) and singlet oxygen ( 1 O 2 ) was confirmed by another control experiment under addition of p-benzoquinone (BQ) [59][60] and 9,10-diphenylanthracene (DPA) [61][62] as a superoxide radical and singlet oxygen scavengers. A reduced conversion of 7 % and 26 % was observed, showing that superoxide radical and singlet oxygen were formed in the photocatalytic reaction and acted as oxidant species in the catalytic cycle.…”

Section: Analysis Of the Probable Photocatalytic Mechanismmentioning

confidence: 94%

Efficient Photocatalytic Oxidation of Aromatic Alcohols over Thiophene‐based Covalent Triazine Frameworks with A Narrow Band Gap

et al. 2020

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Photocatalytic selective oxidation of aromatic alcohols by covalent organic frameworks (COFs) is a sustainable strategy to replace present metal‐based heterogeneous catalytic oxidation systems. Covalent triazine‐based frameworks (CTFs), a subgroup of COFs, possess promising properties as efficient catalysts for photocatalytic oxidation. Sulfur‐containing metal‐free CTFs exhibit a good performance in photocatalysis due to their narrowed band gap, and the fast generated photoelectrons/holes separation and transfer. Here, we report the synthesis of thiophene‐based CTFs under mild conditions for photocatalytic oxidation of aromatic alcohols to the corresponding benzaldehydes using pure oxygen as the oxidant. Full conversion and a selectivity as high as 90 % to benzaldehyde were obtained paving the way for a potential application of these metal‐free photocatalysts in fine chemicals synthesis.

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Section: Analysis Of the Probable Photocatalytic Mechanismmentioning

confidence: 94%

Efficient Photocatalytic Oxidation of Aromatic Alcohols over Thiophene‐based Covalent Triazine Frameworks with A Narrow Band Gap

et al. 2020

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“…O 2 C À was detected by a quenching method via combined use of DCFH and the quencher of O 2 C À , 1,4-benzoquinone (BQ). [14] The fluorescence intensity of DCFH hardly changed in the presence of BQ (Figure S15a), meaning that no O 2 C À was generated. Methylene blue (MB) was used as the probe of OHC.…”

Section: Methodsmentioning

confidence: 99%

Aggregation‐Enhanced Sonodynamic Activity of Phthalocyanine–Artesunate Conjugates

Zhao

et al. 2021

Angew Chem Int Ed

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The clinical prospect of sonodynamic therapy (SDT) has not been fully realized due to the scarcity of efficient sonosensitizers. Herein, we designed phthalocyanine–artesunate conjugates (e.g. ZnPcT4A), which could generate up to ca. 10‐fold more reactive oxygen species (ROS) than the known sonosensitizer protoporphyrin IX. Meanwhile, an interesting and significant finding of aggregation‐enhanced sonodynamic activity (AESA) was observed for the first time. ZnPcT4A showed about 60‐fold higher sonodynamic ROS generation in the aggregated form than in the disaggregated form in aqueous solutions. That could be attributed to the boosted ultrasonic cavitation of nanostructures. The level of the AESA effect depended on the aggregation ability of sonosensitizer molecules and the particle size of their aggregates. Moreover, biological studies demonstrated that ZnPcT4A had high anticancer activities and biosafety. This study thus opens up a new avenue the development of efficient organic sonosensitizers.

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“…Additionally, other chemical or spin traps without such specificity are also known, such as the •O 2 − scavenger Tiron [110] which is oxidized non-specifically by electron donors [111] to its semiquinone radical. These and other quinone based chemical traps are useful in detecting photo-induced radical species [112,113] not primarily via EPR or NMR, but rather via chromatography [112], whereby the extent of modification induced via •O 2 − can be evaluated by SOD [94,111]. Hydrogen peroxide (H 2 O 2 ) (Table 3) is a secondary product, generated via the type I photo-oxidation pathway by electron transfer [114,115]…”

Section: Singlet Oxygen ( 1 O2)mentioning

confidence: 99%

Photo-Oxidation of Therapeutic Protein Formulations: From Radical Formation to Analytical Techniques

et al. 2021

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UV and ambient light-induced modifications and related degradation of therapeutic proteins are observed during manufacturing and storage. Therefore, to ensure product quality, protein formulations need to be analyzed with respect to photo-degradation processes and eventually protected from light exposure. This task usually demands the application and combination of various analytical methods. This review addresses analytical aspects of investigating photo-oxidation products and related mediators such as reactive oxygen species generated via UV and ambient light with well-established and novel techniques.

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Photochemical reactions between 1,4-benzoquinone and O2•−

Cited by 70 publications

References 56 publications

Efficient Photocatalytic Oxidation of Aromatic Alcohols over Thiophene‐based Covalent Triazine Frameworks with A Narrow Band Gap

Efficient Photocatalytic Oxidation of Aromatic Alcohols over Thiophene‐based Covalent Triazine Frameworks with A Narrow Band Gap

Aggregation‐Enhanced Sonodynamic Activity of Phthalocyanine–Artesunate Conjugates

Photo-Oxidation of Therapeutic Protein Formulations: From Radical Formation to Analytical Techniques

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