[article]
Titre : |
3,3'-Dinitrophenolsulphonephthalein : an acid–base indicator dye with unusual properties |
Type de document : |
texte imprimé |
Auteurs : |
Nicolay O. Mchedlov-Petrossyan, Auteur ; Anna N. Laguta, Auteur ; Sergey V. Shekhovtsov, Auteur ; Sergey V. Eltsov, Auteur ; Tatyana A. Cheipesh, Auteur ; Irina V. Omelchenko, Auteur ; Oleg V. Shishkin, Auteur |
Année de publication : |
2017 |
Article en page(s) : |
p. 135-144 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Cellules Chromatographie en phase liquide à hautes performances Colorants -- Synthèse Etude in vitro Photochimie Spectrométrie de masse Structure moléculaire Thiols
|
Index. décimale : |
667.2 Colorants et pigments |
Résumé : |
This paper is devoted to the phenolsulphonephthalein nitro derivative 3,3'-dinitrophenolsulphonephthalein, also called nitrophenol violet (NPV). The neutral molecular form, H2R, was isolated as a sultonic tautomer, and an X-ray crystal structure analysis was carried out. UV-vis absorption spectra in methanol, DMSO, acetonitrile, and water at different pH values were ascribed to the molecular and anionic (H2R, HR-, and R2-) species. Whereas the pKa values of this acid–base indicator (HR- urn:x-wiley:14723581:media:cote12254:cote12254-math-0001 R2- + H+) in water and DMSO are close to those of 3,3',5,5'-tetrabromophenolsulphonephthalein (or bromophenol blue), replacing the four Br atoms with two NO2 groups results in a pronounced tendency to carbinol formation. In weakly acidic aqueous media, the HR- anion slowly converts into the colourless carbinol H2ROH-. The latter is transformed to the orange carbocation only in concentrated (70-94 wt%) sulphuric acid. The formation of H2ROH- is atypical for the common sulphonephthalein indicators and should be ascribed to the enhanced positive charge density on the nodal carbon atom. The reaction mechanism and kinetic equation explaining this pH-dependent process are proposed, in addition to a kinetic study of the common process R2- + HO- -> ROH3- in the alkaline region. The numerical characterisation of the protolytic processes obtained for NPV is also helpful in gaining a better understanding of the properties of previously studied 3,3',5,5'-tetranitrophenolsulphonephthalein, which is much less accessible for a quantitative description. |
Note de contenu : |
- EXPERIMENTAL : General - Synthesis - Photochemical experiments - Studies of the spectroscopic response of the dyes to thiols - UPLC/MS analyses - Determination of cell viability and studies of the response to thiols in living cells
- RESULTS AND DISCUSSION : Synthesis and spectroscopic studies - Studies of the spectroscopic response to thiols - UPLC and mass spectral analyses of products formed in the reaction with L-Cys - Cell viability and response to thiols in vitro |
DOI : |
10.1111/cote.12254 |
En ligne : |
https://drive.google.com/file/d/1korHDoZ5IQTDhl4kyBlpyXX3OPlzMqdG/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28227 |
in COLORATION TECHNOLOGY > Vol. 133, N° 2 (04/2017) . - p. 135-144
[article]
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