3,3'-Dinitrophenolsulphonephthalein : an acid–base indicator dye with unusual properties / Nicolay O. Mchedlov-Petrossyan in COLORATION TECHNOLOGY, Vol. 133, N° 2 (04/2017)  

[article]  inCOLORATION TECHNOLOGY > Vol. 133, N° 2 (04/2017) . - p. 135-144 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 [article]

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Revisiting tetranitrophenolsulfonephthalein / Nicolay O. Mchedlov-Petrossyan in COLORATION TECHNOLOGY, Vol. 131, N° 3 (06/2015)  

[article]  inCOLORATION TECHNOLOGY > Vol. 131, N° 3 (06/2015) . - p. 236-244 Titre : Revisiting tetranitrophenolsulfonephthalein Type de document : texte imprimé Auteurs : Nicolay O. Mchedlov-Petrossyan, Auteur ; Kateryna V. Roshchyna, Auteur ; Sergey V. Shekhovtsov, Auteur ; Sergey V. Eltsov, Auteur ; Oleksii S. Zozulia, Auteur ; Irina V. Omelchenko, Auteur ; Oleg V. Shishkin, Auteur Année de publication : 2015 Article en page(s) : p. 236-244 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Colorants -- Synthèse Nitrophénols Index. décimale : 667.2 Colorants et pigments Résumé : Among the vast series of phenolsulfonephthalein dyes, the nitro derivatives and especially 3,3?,5,5?-tetranitrophenolsulfonephthalein (nitrophenol crimson) remain practically unexplored, whereas the halogen and alkyl derivatives have been studied comprehensively. This striking difference is probably due to the enormous influence of the four NO2 groups on the properties of the dye. As a result, the protolytic behaviour is unlike even that of tetrabromo phenolsulfonephthalein, and the recognised scheme of acid–base and tautomeric equilibrium of the sulfonephthaleins is unable to explain it. The molecular form H2R was isolated as a sultonic tautomer, and an X-ray crystal structure analysis was carried out. Our studies of the UV-vis absorption spectra in water, methanol, dimethyl sulfoxide, acetonitrile, acetone, and dichloromethane, as well as in aqueous micellar solutions of surfactants, allowed us to evaluate the true molar absorptivity of the dianion R2?, and to elucidate the enormous tendency to form yellow trianionic carbinol ROH3?, even in the presence of traces of H2O. Nuclear magnetic resonance and electrospray data confirm the proposed scheme of ionisation and tautomerism of nitrophenol crimson. Note de contenu : - EXPERIMENTAL : Materials - Synthesis of the dye - Apparatus - Kinetic measurements - RESULTS AND DISCUSSION : The structure of the dye in the solid state - Nitrophenol crimson in water - Nitrophenol crimson in organic solvents - Examining nitrophenol crimson solutions by the electrospray method - The monoanion problem DOI : 10.1111/cote.12145 En ligne : https://onlinelibrary.wiley.com/doi/epdf/10.1111/cote.12145 Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24126 [article]

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