Reactions of oxidizing radicals with 2- and 3-aminopyridines: a pulse radiolysis study

Dey, G.R.; Naik, D.B.; Dwibedy, P.; Kishore, Kamal

doi:10.1016/s0969-806x(01)00581-3

Cited by 5 publications

(7 citation statements)

References 19 publications

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“…Moreover, sulphate radical reaction at the nitrogen position of 3-substituted pyridine molecules is not supported by our experimental results showing no pyridine N-oxide formation as a reaction product. The observed results are in agreement with reported data giving no definite indication on the occurrence of HOC attack at the nitrogen site [27,28] and with reported SCF MO calculations indicating that delocalization of the odd electron in the hydroxylpyridine adducts favors their generation rather than hydroxyl addition to the N atom. [29] Contrary to our observations, Dey et al [28] suggested that an electron transfer was the preferred channel for the reaction of 3-aminopyridine with sulphate radicals.…”

Section: Discussionsupporting

confidence: 92%

“…The observed results are in agreement with reported data giving no definite indication on the occurrence of HOC attack at the nitrogen site [27,28] and with reported SCF MO calculations indicating that delocalization of the odd electron in the hydroxylpyridine adducts favors their generation rather than hydroxyl addition to the N atom. [29] Contrary to our observations, Dey et al [28] suggested that an electron transfer was the preferred channel for the reaction of 3-aminopyridine with sulphate radicals. The one-electron oxidation potential of pyridine derivatives diminishes considerably with increasing electron donor ability of the substituents.…”

Section: Discussionsupporting

confidence: 92%

“…A rate constant k OX = 7 10 6 m À1 s À1 is reported for the reaction of O 2 with the hydroxyl adduct of 3-aminopyridine. [28] The reaction rates of O 2 with HCHD radicals increase with increasing electron donor ability of the substituents. [30] Assuming a similar behavior for the hydroxypyridine radical adducts, the reaction rate constant for the adducts studied here should be < 7 10 6 m À1 s…”

mentioning

confidence: 99%

“…On the other hand, k OX = 1 10 8 m À1 s À1 is reported for the reaction of O 2 with the hydroxyl adduct of 2-aminopyridine, [28] thus indicating that the substitution site strongly influences the easiness of mineralization of the pyridine moiety.…”

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confidence: 99%

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Reactions of Sulphate Radicals with Substituted Pyridines: A Structure–Reactivity Correlation Analysis

et al. 2007

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The kinetics of the oxidation of pyridine, 3-chloropyridine, 3-cyanopyridine, 3-methoxypyridine and 3-methylpyridine mediated by SO4 () radicals are studied by flash photolysis of peroxodisulphate, S2O8(2-), at pH 2.5 and 9. The absolute rate constants for the reactions of both, the basic and acid forms of the pyridines, are determined and discussed in terms of the Hammett correlation. The monosubstituted pyridines react about 10 times faster with sulphate radicals than their protonated forms, the pyridine ions. The organic intermediates are identified as the corresponding hydroxypyridine radical adducts and their absorption spectra compared with those estimated employing the time-dependent density functional theory with explicit account for bulk solvent effects. A reaction mechanism which accounts for the observed intermediates and the pyridinols formed as products is proposed.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 92%

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confidence: 99%

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confidence: 99%

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Reactions of Sulphate Radicals with Substituted Pyridines: A Structure–Reactivity Correlation Analysis

et al. 2007

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“…4A was recorded at 2 s after the pulse. Under our conditions, it is worth to recall that the solvated electron is scavenged by N 2 O leading to an additional way for the formation of hydroxyl radicals [39,41]. The obtained spectrum is characterized by two well-defined absorption bands at 360 and 540 nm.…”

Section: Pulse Radiolysismentioning

confidence: 94%

Degradation of metsulfuron methyl by heterogeneous photocatalysis on TiO2 in aqueous suspensions: Kinetic and analytical studies

Rafqah

Wong-Wah-Chung

Aamili

et al. 2005

Journal of Molecular Catalysis A: Chemical

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Photoinduced Electron Transfer Between Pyridine Coated Cadmium Selenide Quantum Dots and Single Sheet Graphene

Guo

Bao

Upadhyayula

et al. 2013

Adv Funct Materials

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Interest in graphene as a two‐dimensional quantum‐well material for energy applications and nanoelectronics has increased exponentially in the last few years. The recent advances in large‐area single‐sheet fabrication of pristine graphene have opened unexplored avenues for expanding from nano‐ to meso‐scale applications. The relatively low level of absorptivity and the short lifetimes of excitons of single‐sheet graphene suggest that it needs to be coupled with light sensitizers in order to explore its feasibility for photonic applications, such as solar‐energy conversion. Red‐emitting CdSe quantum dots are employed for photosensitizing single‐sheet graphene with areas of several square centimeters. Pyridine coating of the quantum dots not only enhances their adhesion to the graphene surface, but also provides good electronic coupling between the CdSe and the two‐dimensional carbon allotrope. Illumination of the quantum dots led to injection of n‐carrier in the graphene phase. Time‐resolved spectroscopy reveals three modes of photoinduced electron transfer between the quantum dots and the graphene occurring in the femtosecond and picosecond time‐domains. Transient absorption spectra provide evidence for photoinduced hole‐shift from the CdSe to the pyridine ligands, thereby polarizing the surface of the quantum dots. That is, photoinduced electrical polarization, which favors the simultaneous electron transfer from the CdSe to the graphene phase. These mechanistic insights into the photoinduced interfacial charge transfer have a promising potential to serve as guidelines for the design and development of composites of graphene and inorganic nanomaterials for solar‐energy conversion applications.

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Reactions of oxidizing radicals with 2- and 3-aminopyridines: a pulse radiolysis study

Cited by 5 publications

References 19 publications

Reactions of Sulphate Radicals with Substituted Pyridines: A Structure–Reactivity Correlation Analysis

Reactions of Sulphate Radicals with Substituted Pyridines: A Structure–Reactivity Correlation Analysis

Degradation of metsulfuron methyl by heterogeneous photocatalysis on TiO2 in aqueous suspensions: Kinetic and analytical studies

Photoinduced Electron Transfer Between Pyridine Coated Cadmium Selenide Quantum Dots and Single Sheet Graphene

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