Spectrophotometric determination of aromatic amines by reaction with p-benzoquinone

Iskander, Madlene L.; Medien, H. A. A.; Nashed, S.

doi:10.1016/0026-265x(87)90180-9

Cited by 13 publications

(5 citation statements)

References 11 publications

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“…This suggests that the absorbance at 380 nm is not characteristic of the main dye but rather represents a separate compound, henceforth labeled chromogen 380. A similar behavior in the aniline/ p -benzoquinone system was reported in ref .…”

Section: Introductionsupporting

confidence: 87%

Identity of a Purple Dye Formed by Peroxidic Oxidation of p-Aminophenol at Low pH

Lerner

2011

J. Phys. Chem. A

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The structure of a colored intermediate commonly formed in the oxidation of p-aminophenol at low pH is established by analysis of H NMR and UV/vis spectra, kinetics, and molecular modeling, following a new method for synthesizing the dye in high concentrations. The chromogen is shown to consist of two compounds with absorption maxima at 540-560 and 375-385 nm. The 2,6-dimethyl and 3,5-dimethyl analogues of p-aminophenol are found to undergo N- rather than C-substitution under similar conditions.

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Section: Introductionsupporting

confidence: 87%

Identity of a Purple Dye Formed by Peroxidic Oxidation of p-Aminophenol at Low pH

Lerner

2011

J. Phys. Chem. A

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“…Although Hammett σ and σ + constants are available for most meta and para substituents, there is a very limited data set for ortho substituents ( , ). Successful correlations based on Hammett σ and σ + constants have been observed for the nucleophilic addition of substituted anilines to benzoquinone ( , ) and the oxidation of substituted anilines by MnO 2 ( , ).…”

Section: Resultsmentioning

confidence: 99%

“…The transition states for the nucleophilic addition of anilines Correlations of basicity with nucleophilicity have been observed over restricted ranges of basicity (18). Of special significance is the observation that log k (first-order rate constant) versus pK a for the nucleophilic addition of a series of meta-and para-substituted anilines with benzoquinone were linear (19). Quinone moieties are thought to be the dominant site for the nucleophilic addition of aromatic amines to natural organic matter (12,13,20).…”

Section: Resultsmentioning

confidence: 99%

Sediment-Associated Reactions of Aromatic Amines. 2. QSAR Development

Colon

Weber

Baughman

2002

Environ. Sci. Technol.

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The fate of aromatic amines in soils and sediments is dominated by irreversible binding through nucleophilic addition and oxidative radical coupling. Despite the common occurrence of the aromatic amine functional group in organic chemicals, the molecular properties useful for predicting reaction kinetics in natural systems have not been thoroughly investigated. Toward this goal, the sorption kinetics for a series of anilines with substituents in the ortho, meta, or para positions were measured in sediment slurries. The sorption kinetics of the substituted anilines were characterized by an initial, rapid sorption process followed by a much slower sorption process. The initial rates of sorption varied with the type and position of the substituent group. Rate constants for the initial sorption process were correlated with molecular descriptors, including dissociation constants (pKa's), Hammett sigma constants, polarographic half-wave potentials (E1/2), one-electron oxidation potentials (E1), highest occupied molecular orbital (HOMO) energies (E(HOMO)), and ionization energies (E(IE)). On the basis of the strength of linear correlations and the availability of data, dissociation constants and Hammett sigma constants appear to be the most useful molecular descriptors for predicting reaction rates of substituted anilines in the sediment slurries. The slow rates of sorption were much less sensitive to substituents effects than the rate constants for the faster sorption process, suggesting that the slower process was not controlled by the rate of electron transfer (i.e., nucleophilic addition or radical formation) but was limited by the availability of covalent binding sites.

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“…Three different ammonium acetate solutions were prepared in order to dissolve all of the quinones, as indicated in It is known that BQU is reactive with primary amines4*' and it has been suggested that BQU may act as a good derivatization reagent for aromatic amines. 6 The reaction of BQU with primary amines was reported to be insensitive to the presence of ammonia., A possible origin for the m/z 124 peak in 0.1 M ammonium acetate aqueous is amine conjugate formation with BQU as shown in Fig. 2, scheme 1.…”

Section: Methodsmentioning

confidence: 99%

Unique thermospray mass spectrometry of 1,4‐benzoquinone and analogs in ammonium acetate solutions

Gctek

Vestal

Vestal³

et al. 1991

Org. Mass Spectrom.

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In general, iom corresponding to [ M + HI+ and/or IM + NH,] + are observed in thermospray mass spectrometry (TSMS) when using ammonium acetate in the liquid carrier. For several quinones investigated, unique thermospray mass spectra were detected with a mass spectral peak corresponding to an I M + 161 + ion being observed in aqueous ammonium acetate solutions. Investigation of 1,dbenzoquinone (BQU) and structurally analogous quinones indicated that amhe conjugate formation with BQU and similar quinones was the on'gin of the unique IM + 161+ ion in E M S . When methanol was added to the liquid carrier, ions corresponding to methoxy conjugation were detected. Higb-performance liquid chromatography followed by TSMS or electrochemical detection gave evidence that this amiw and methoxy conjugate formation was occurring in the thermospray source area.

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Spectrophotometric determination of aromatic amines by reaction with p-benzoquinone

Cited by 13 publications

References 11 publications

Identity of a Purple Dye Formed by Peroxidic Oxidation of p-Aminophenol at Low pH

Identity of a Purple Dye Formed by Peroxidic Oxidation of p-Aminophenol at Low pH

Sediment-Associated Reactions of Aromatic Amines. 2. QSAR Development

Unique thermospray mass spectrometry of 1,4‐benzoquinone and analogs in ammonium acetate solutions

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