- A highly selective and sensitive colorimetric chemosensor for Fe2+ based on fluoran dye
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A highly selective chemosensor based on fluoran dye for Fe2+, 2′-anilino-3′-methyl-6′-dibuthylamino-N-((2′-(2″-ethylimino) methyl) naphthalen-2-ol) iso-indolin-1-one-fluoran (5), was designed and synthesized. The chemical structures of all the intermediates and the fluoran dye 5 are characterized by 1H NMR, 13C NMR, Ms and elemental analysis. Upon addition of Fe2+, the fluoran dye 5 shows a new peak around 658 nm in its absorption spectra, and the color of solution changed from colorless to greenish black. Whereas other ions including Mg2+, Pb2+, Ni2+, Hg2+, Cd2+, Fe3+, Cu2+, Zn2+ and Al3+ and so on induced basically no spectral change, which constituted a Fe2+ highly sensitive and selective colorimetric chemosensor by naked eyes .
- Wang, Sheng,Gwon, Seon-Yeong,Kim, Sung-Hoon
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- 13CNMR and Electronic Absorption Spectroscopic Studies on the Equilibrium between the Colorless Lactone and the Colored Zwitterion Forms of a Fluoran-Based Black Color Former
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The equilibrium between the colorless lactone (L) and the colored zwitterion (Z) forms of the fluoran compound 1, which has been widely used as a typical black color former in data-recording systems, has been studied by 13CNMR and electronic absorption spectroscopies. Fluoran 1 showed no visible absorption in aprotic solvents, while a black color appeared in phenolic solvents. The 13CNMR and signal of the spiro carbon of 1 in CDCl3 appeared at 84.2ppm, indicating that 1 exists substantially as L in aprotic solvents. In phenol d6 at 50°C, the signal of the spiro carbon in 1 shifted to a lower magnetic field and appeared in the sp2-hybridization region (δ = 162.7), suggesting that in phenol-d6 a cleavage of the C(spiro)-O bond in the lactone ring occurs and that the ring-opened Z form is produced. The equilibrium between L and Z depended strongly on the temperature and solvents. The high temperature and inhibition of the solute (1)-solvent interaction by steric hindrance, self-association and intramolecular chelation of the solvent shifted the L-Z equilibrium toward L. The thermodynamic parameters for the equilibrium reaction in phenolic solvents were also estimated.
- Yanagita, Mitsuhiro,Aoki, Izuo,Tokita, Sumio
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- Kass-controlled Hg2+ transport from Crystal Violet Lactone to Fluoran
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We have investigated the Hg2+ transport from Crystal Violet Lactone to Fluoran dye based on the association constant, Kass. Upon addition of Hg2+, the Crystal Violet Lactone shows a new peak at around 603 nm, and the color of the solution changed from colorless to blue. With the addition of Fluoran dye in this solution containing Crystal Violet Lactone and Hg2+, the absorption intensity of Fluoran dye at 447 nm and 586 nm was all increased. So the color of solution gradually became black from blue color. From the changes of the ratio A586/A447, it is apparent that the Hg2+ in Crystal Violet Lactone-Hg 2+ was transported to colored Fluoran. The Hg2+ transport from Crystal Violet Lactone to Fluoran dye was also carried out by the calculation of the association constant: the binding ability for the complex formation of Fluoran dye and Crystal Violet Lactone-Hg2+ is much greater in CH3CN solution (Kass = 3.0 × 10 4 M-1) than that of the Crystal Violet Lactone with Hg2+ (Kass = 1.2 × 103 M-1).
- Lee, Eun-Mi,Gwon, Seon-Yeong,Ji, Byung-Chul,Kim, Sung-Hoon
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- Preparation method for fluorine color former
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The invention especially relates to a preparation method for a fluorine color former, belonging to the field of organic dyes. The preparation method comprises the following steps: mixing a phenol derivative, phthalic anhydride and toluene in a flask, and carrying out stirring, heating and a reaction; after completion of the reaction, carrying out cooling to room temperature, then carrying out filtering, washing a filter cake with an alcohol solvent, and carrying out drying to obtain a pale yellow solid; dissolving the pale yellow solid in concentrated sulfuric acid with a mass fraction of 90-102%, and carrying out stirring to form a uniform solution; adding a m-diphenylamine substituendum and carrying out a reaction; adding a solution obtained after the reaction in the previous step into an ice water mixture, and carrying out stirring for a period of time; then carrying out filtering, dissolving a filter cake in toluene, then adding an aqueous solution of inorganic alkali, carrying outstirring and heating reflux for a period of time; then successively carrying out cooling and standing for layering so as to separate an aqueous phase and an organic phase; and subjecting the organicphase to drying, concentration and crystallization so as to obtain the finished fluorine color former. The preparation method of the invention improves traditional process routes, uses a phenol derivative as a novel reaction raw material, avoids the formation of the by-product rhodamine dye, and is high in the purity and yield of the product fluorine color former.
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Paragraph 0038; 0039; 0040
(2018/07/30)
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- Method for preparing black fluorane thermal-pressure sensitive dye by virtue of one-step method
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The invention discloses a method for preparing a black fluorane thermal-pressure sensitive dye by virtue of a one-step method. The method comprises the following steps: (1) acid-catalysis cyclic condensation: adding a diphenyl ketone derivative and 2-methyl-4-methoxydiphenylamine into an organic solvent I with a relatively low boiling point, adding a sulfuric acid solution while stirring, and heating to a reflux temperature to react for 1.5-4.5 hours; and (2) post-processing refining: adding water into reaction liquid obtained in the step (1), recycling the organic solvent I with the relatively low boiling point by virtue of heat release, then adding a nonpolar solvent II into the recycled reaction liquid, carrying out heating reflux to separate a water phase so as to obtain an organic phase, carrying out cooling, crystallization, filtering and solvent washing on the organic phase, and drying, so as to obtain the black fluorane thermal-pressure sensitive dye.
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Paragraph 0059-0078
(2017/04/29)
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- Highly selective colorimetric signaling of iron cations based on fluoran dye
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A highly selective colorimetric chemosensor based on fluoran dye for iron cations, 2′-anilino-3′methyl-6′-dibuthylamino-N-(2′- (2″-hydroxybenzylideneamino)ethyl) iso-indolin-1-one-fluoran (5), was designed and synthesized. The chemical structures of all t
- Wang, Sheng,Gwon, Seon-Yeong,Son, Yong-A,Matsumoto, Shinya,Hwang, In Jeong,Kim, Sung-Hoon
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scheme or table
p. 155 - 163
(2012/08/08)
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