630-98-8Relevant articles and documents
Kinetics of fading of some triphenylmethane dyes: Effects of electric charge, substituent, and aqueous binary mixtures of dimethyl sulfoxide and 2-propanol
Samiey,Dalvand
, p. 60 - 70 (2014/01/06)
The rate constants of alkaline fading of a number of triphenylmethane (TPM) dyes including methyl green (ME2+), brilliant green (BG +), fuchsin acid (FA2-), and bromophenol blue (BPB 2-) were obtained in aqueous binary mixtures of 2-propanol (protic solvent) and dimethyl sulfoxide (DMSO) (aprotic solvent) at different temperatures. It was observed that the reaction rate constants of BG+ and ME2+ increased and those of FA2- and BPB2- decreased with an increase in weight percentages of aqueous 2-propanol and DMSO binary mixtures. 2-Propanol and DMSO interact with the used TPM molecules through hydrogen bonding and ion-dipole interaction, respectively, in addition to their hydrophobic interaction with TPM dyes. The fundamental rate constants of a fading reaction in these solutions were obtained by the SESMORTAC model. Also, the effect of electric charge and substituent groups of a number of TPM dyes on their alkaline fading rate was studied.
Equilibrium and Kinetic Studies on the Formation of Triphenylmethanols from Triphenylmethane Dyes
Hagiwara, Takuyuki,Motomizu, Shoji
, p. 390 - 397 (2007/10/02)
For five kinds of triphenylmethane dyes, the rate constants of hydration and dehydration reactions, and equilibrium constants in an aqueous solution were measured by a stopped-flow method.An increase in the number of dialkylamino groups caused a decrease in the rates and the equilibrium constants of the hydration, and the more the electron-donating effect of the dialkylamino groups, the slower the hydration rate became.The more protonated quinonoids were easily converted to the corresponding alcohols.On the basis of the equilibrium constants, Malachite Green was ascertained to be the best reagent of the five dyes for ion association with heteropolyacids in an aqueous medium.
Effect of Pressure on the Rate of Alkaline Fading of Triphenylmethane Dyes in Cationic Micelles
Taniguchi, Yoshihiro,Iguchi, Akira
, p. 6782 - 6786 (2007/10/02)
The rates of alkaline fading of triphenylmethane dyes in cationic micelles have been measured at pressures up to about 2 kbar and at 25 deg C in 0.1 M Tris buffer solution.These rates follow the kinetics of the Michaelis-Menten type.The volume changes for the incorporation of dyes in the micellar phase are 14-15 cm3/mol for ethyl violet and brilliant green and 3-4 cm3/mol for crystal violet and malachite green.It was confirmed that these differences are due to the hydrophobicity of dyes.The activation volumes for the fading reaction in micellar phases are positive except in the case of the crystal violet-cetyltrimethylammonium bromide micellar system.However, the activation volumes in nonmicellar aqueous solutions are negative.The differences of the activation volumes between micellar and nonmicellar systems are discussed from the point of view of the general base catalysis, which contains both the water and hydroxide ion pathways.It was clear that micelles change the water control into hydroxide ion control.
